I've received a few emails this week from readers who receive content via email in regards to charts being overlaid on top of text. The platform I write the blog on introduced a new editor which I switched over to this week, so this most likely would be the problem. I am also not sure if this is an issue only in Internet Explorer or both IE and Firefox, I'll be able to tell tonight.
Unfortunately, Google bought Blogger.com which is the platform I use for the website, and their human technical support ranges from zilch to none. Any issues are posted on a message board and that's about all you can do.
I've only heard from a handful of people so I don't know if this is widespread (email me if you are having that problem as well) but I will keep looking into the issue and if its more prevalent than just a few readers will look to switch back to the older editor this weekend.