Tools > Options > Content > Load Images > make sure the "For Originating Website Only" selection is UNclicked, and while you're at it click on Advanced Settings and try adding hometheaterforum.com as being allowed to load images -- as well as any variation on the URL that maybe is where your banners come from.
Probably won't do anything, but worth looking around in there if you haven't already.
Are you on a broadband connection? Try installing the Fasterfox extension but run it in Optimized mode. I was having problems with the web page not loading correctly in Turbo Charged mode and when I slowed it down to Optimized the web pages loaded correctly with only a small penalty in load times.
Parker, Did you ever resolve this? I noticed that MS Live, MS adCenter, and IE7 are all not compatible with the newest FF version.
I also noticed it appears you downloaded a beta of IE7, then removed it. Could IE7 have left some stray bits behind causing your problem? Just a thought.