There have been no changes made to the site since this issue was resolved so I have no idea what the issue could be?
Have there been any recent browser updates for IE?
The only real answer that I can give that I know works is to simply move to a different browser. I've read a number of posts about users having issues with vB/IE and I've yet to find any concrete reasons as to why?
There is an update for vB so I'll install that this weekend but if it doesn't fix your problem I can pretty much guarantee you will need to use a different browser. Sorry d00d but I know the code is clean this time around and there is literally nothing I can do to improve upon the site even with a full re-build.
There may also be a small chance that google was having issues with rendering Adsense in a timely manner and that may have slowed things up enough. This happens surprisingly frequently and I've seen it responsible for not allowing the theme to load now and again.
Lastly, the Server could be experiencing issues such as multiple overlapping crons being run. It may not be a bad idea to just check
http://www.lifesupporters.com/forums and see if there are any issues loading that in IE. BTW, Lifesupporters is my home site so if it is a server issue the chances are that site will be affected the most.