I realize this is an old thread, but it's still relevant. I'm consistently amazed at both the lack of knowledge of many users, and also the willingness to immediately assume "it must be something funky the hosting company is doing."
Seriously?
ModSecurity is a set of rules designed to protect your website/WordPress blog. Yes, there are times it needs to be tweaked/adjusted, as there will never be any security system/firewall that's a plug-and-play one-size-fits-all.
Beyond that, the OP stated the site worked fine in Firefox but not in ie9. That right there should have been a clue it was NOT something the web hosting company did!
The fact is, there's *many* potential issues along the way. It could be a WordPress issue, could be a ModSecurity issue, a firewall issue, and server software (of which there are hundreds) upgrade compatibility issue. I'll wholeheartedly agree that it sounds like the hosting tech support was a little too quick to say there was no problem on their end...but we also don't know how detailed you were in your requests, etc. Then again, at less than $10 a month, you get what you pay for.
My general point (and yes, I do have one) is that time and time and time again in this forum and others, I see users taking about 30 seconds to research their issue, and if the answer doesn't smack them in the face, then it must be the host's fault. If you buy a car, you take the time to learn how to drive it, and many years perfecting that skill. Put at least as much effort into learning what you're doing when you install a script that's on the Internet and a target to every hacker over the age of 5.
