Blackberry users have now entered their third straight day of outages, with the blackout on services now having spread to North America.

Millions of users in Europe, Middle East and India have been stranded without service for 72 hours.

Service was briefly restored on Tuesday for a few hours, but then disrupted once again.

Research-in-Motion Ltd. (Nasdaq: RIMM), the company that manufactures the Smartphone, released a vague statement on the Blackberry’s woes on Tuesday evening but failed to declare when service would be restored.

The messaging and browsing delays being experienced by BlackBerry users in Europe, the Middle East, Africa, India, Brazil, Chile and Argentina were caused by a core switch failure within RIM’s infrastructure, the company said.

Although the system is designed to failover to a back-up switch, the failover did not function as previously tested. As a result, a large backlog of data was generated and we are now working to clear that backlog and restore normal service as quickly as possible. We apologize for any inconvenience and we will continue to keep you informed.

Meanwhile, according to reports, Blackberry users around the world are angry and frustrated by the absence of services, including mobile internet access, email and Blackberry Messenger (BBM), the instant messenger.

The service outage occurs at a very fragile time for RIM – the company is reportedly seeking to be acquired. Moreover, giant rival Apple (Nasdaq: AAPL) is launching it much-publicized new iPhone 4S Smartphone.

Ian Fogg, an analyst at Forrester Research, wrote on his blog: RIM is in danger of becoming its own worst enemy if it is unable to reliably operate the communication services that have differentiated it. BBM is the reason many young consumers stay with BlackBerry. If it doesn’t work, they will leave RIM.

Indeed, RIM has already lost significant market share to Apple and the Android operating system.

Richard Windsor, global technology specialist at Nomura International, told media: It's a blow upon a bruise. It comes at a bad time. One possibility could be that it encourages client companies to look more at other options such as allowing users to connect their own devices to the corporate server and save themselves the cost of buying everyone a BlackBerry.

Lord Alan Sugar, a British entrepreneur and television personality, fumed on his Twitter account: In all my years in IT biz, I have never seen such [an] outage as experienced by Blackberry. I can't understand why it's taking so long to fix. All my companies use [Blackberries], every one so reliant on getting email on the move, people don't know if they are coming or going.

Similarly, Alastair Campbell, the former communications chief for ex-British Prime Minister Tony Blair, criticized RIM’s handling of the service disruption.

Explain while you fix. Apologize when you have. Recompense after. Handling so far woeful, he said, according to the Daily Telegraph.