Mac users have been able to play with Apple's new big cat, OS X Mountain Lion, for roughly 24 hours at this point. Though the initial reviews were overwhelmingly positive, we mentioned that it was still early in the day, and as Apple users had a chance to explore Mountain Lion, they would inevitably find some bugs and errors. And that's exactly what happened.

For a quick primer on Apple's new operating system for the Mac, Mountain Lion is the company's attempt to seamlessly blend the traditional features of its desktop platform (Mac OS) with the wildly popular features of the iOS platform for iPhone and iPad, including intuitive gestures and more options for sharing content, staying organized and communicating with each other. OS X Mountain Lion's 200+ features are laid out in our online guide.

But rarely is the first version of a new operating system perfect. Every major software upgrade comes with its fair share of bugs and omissions, especially when new software hits an old piece of hardware. Apple, despite its incredible talents, is unfortunately no different from most tech companies in this regard.

I posted a few articles during yesterday's launch warning users about the dangers of being among the first adopters of a new operating system. Those brave enough to take the risk have found that while Mountain Lion is a big step up, it is not without its flaws, bugs, errors and incompatibilities, especially with third-party apps. I detailed a few of these complaints early yesterday, but I received more reader emails overnight. Here's what new Mountain Lion users had to say:

Michael Karellas discovered an issue with a Microsoft program, which shouldn't be a major surprise to anyone:

"I upgraded to Mountain today," Karellas said. "Since the upgrade, I have not been able to log into Outlook, getting an invalid password error. I can log on via the web access to my Outlook account, so I know my password is correct. I ran Office 2011 auto-update as well."

Karellas, the good guy that he is, followed up his first email with a fix for the problem he was experiencing once he discovered it himself.

Andrew Arnold gave Mountain Lion a review of "1 out of 5 stars," nothing that he is "one of many who has a top-of-the-line system who expects top-of-the-line results," but got less than he hoped for.

"I purchased, downloaded, and installed the new system several times and found it lacking," Arnold said. "Actually, more than lacking, and more destructive. System files lock up and are unresponsive. No, my system isn't tricked out, so I'm having to take it in for fixes. Thanks Apple! I love paying for your testing."

Arnold is the second person we've heard of with Mountain Lion complaints while using a top-of-the line system. On Wednesday, Gizmodo's Jesus Diaz discovered a few issues with his computer's speed, most interestingly while using Apple's latest laptop, the MacBook Pro with Retina Display.

"I used this computer for reviewing the final version of OS X 10.8 and, while it was perfect with Lion, the display is now very buggy," Diaz wrote.

"The zooming is often slow, the cursors sometimes disappear, some parts of the text fields don't refresh properly in Safari, animated GIFs get garbled frequently, and videos sometimes get distortions, especially if you try to rotate them in QuickTime Player. At times, there is also a perceptible slowdown, even while this is a fully loaded system with 16GB of RAM.

"Perhaps this is a problem unique to my computer, but I doubt it. None of these problems were present with the factory-installed OS X Lion. And this computer was almost virgin before the upgrade from Lion to Mountain Lion."

Since the first complaints seemed to come from owners of new Macs, we asked for any issues that arose with users of older models. Apple says that Mountain Lion is compatible with a handful of Mac Models, including 2007 iMacs and later, the late-2008 aluminum MacBooks and the 2009 MacBooks, all MacBook Pros that debuted after 2007, as well as MacBook Airs and Mac Pros after 2008. Apple has also made Mountain Lion compatible with 2009 Mac Mini models and later, as well as Xserve devices.

Natan Vigna, who owns a mid-2009 15-inch MacBook Pro with a 2.8 GHz Intel Core 2 Duo, said that OS X Mountain Lion is "painfully slow" on his machine.

"The only thing I see is the beach ball of death every two to five seconds," Vigna said in reference to Apple's loading icon. "I'm glad I only upgraded my toy laptop and not my real work machines that I use for work."

Vigna also noted that Safari was acting slow for him and that the track pad didn't work well - "It won't click on links or does when it feels like it," he says - and he's not of Apple's Dictation feature either, calling it "half good, half useless." He said he'd "keep complaining but it's taking too long to type this email as I have gotten over 15 beach balls in these five lines."

"The beach ball of death" was the center of another story of frustration with OS X Mountain Lion, submitted by IBTimes community member "kaboom."

"After downloading, accepting user agreements, installing, and rebooting, I get a white screen with a spinning 'loading' wheel. Normally this indicates that it's about to show me the login screen, however, this literally stayed on the screen for HOURS! I reluctantly rebooted only to find the same thing. I used Command-V to see what was getting hung up. 'bootcache.playlist...' was not loading or something like that. I then repaired permissions through the Disk Utility via Restore Mode, but it still didn't work. I did the "chmod -n -R /Volumes" thing and that didn't work. So, now I'm backing up my data before I get nuts and completely erase and start over."

Liam Vasey, an owner of a 2009 MacBook Pro with 8 GB of RAM and a SSD, has noticed display issues since upgrading to 10.8.

"Nothing works on hover," Vasey said. "The dock won't appear as I hover near the bottom of the screen, right click contextual menus don't work in the finder, button and link hovers on the web (any browser) don't work, basically anything I have to hover over with my mouse won't work now."

Interestingly enough, many of the issues have to do with the display, especially video streaming. IBTimes Submitter "Tez Manchester UK" wrote in with his Mountain Lion woes.

"Since upgrading to Mountain Lion last night I can no longer use Netflix and my other media streaming sites. Keeps telling me I have no Internet connection, yet I am still able to surf the Web. Very frustrating. Also I have yet to find the other new features like the mirroring to my Apple TV."

Speaking of Airplay Mirroring, one of the more touted features in OS X Mountain Lion was the center of the submission from IBTimes reader "Red Heron," who found that the service is still only half-baked.

"Airplay Mirroring is a slightly jerky when streaming video movies from Amazon even with a 30 mbs download service," Red Heron said. "It also will not work on MacBook Air models that are more than 18 months old."

Submitter Mark Hutchinson noted two main issues he's encountered with OS X Mountain Lion, the latter issue being significantly more troubling. However, he failed to mention what kind of Mac he owns:

"Safari 6 is no longer working in Google Docs spreadsheets," Hutchinson said. "My 10.8 upgraded system has crashed twice when attempting to come out of screen saver/power mode. Both times I can see and move my mouse pointer but the rest of the screen is black."

Emailer Clint Horsley didn't say what kind of Mac he owned, but noted one bug he found:

"You can't copy a test from an email and paste it into another email or word app," Horsley said. "What is up with that?"

Reader Ronnie Yeoh said that his iMac is having a lot of trouble wrangling OS X Mountain Lion.

"I CANNOT shut down my iMac (mid-2011) computer through the Apple logo," Yeoh said. "'About this Mac, Restart, Sleep, and Force Quit also does not work. I have to press the power button to shut down each time. This is bad."


Apple will likely issue solutions to some of these bugs in the system, but some users are finding ways to get their computers up and running after an initial stumble with OS X Mountain Lion.

"Just did the upgrade on a near-new MacBook Pro with 8 GB and a Hybrid Drive (8GB NAND)," said "Tony from OZ," an IBTimes submitter. "Mine was taking ages to start and shut down and, on a few occasions, would not shut down at all. I reset SMC settings and cleared PRAM and it's back to its old screaming self again!"

Brett Reilly of Social Media SEO has five steps to diagnose all Mountain Lion erros, which involves verifying Disk Permissions with the Disk Utility and resetting the computer's PRAM, which often helps the installation. This comes straight from Apple:

"A small amount of your computer's memory, called "parameter random-access memory" or PRAM, stores certain settings in a location that Mac OS X can access quickly. The particular settings that are stored depend on your type of Mac and the types of devices connected to it. The settings include your designated startup disk, display resolution, speaker volume, and other information."

Reilly explains how to diagnose and fix issues in Mountain Lion on his page.

To any Mac users experiencing any issues, errors or bugs with Mountain Lion, please feel free to write in or leave a comment at the bottom of the page. If you have solutions to any of these issues, please, help out your fellow reader! Be sure to note which kind of Mac (model, year) you own.