thanks - I think this was going to be my next step anyway. Last night, after I started this thread, I tried to get into the Tools>Manage Add-ons just to see what was going on and IE8 threw an error and shut down. This was repeatable, so there's probably something wrong with the install of IE8.
I won't be able to get to that computer until tomorrow evening sometime. I'll have to see if I still have IE7 before I remove IE8.
I don't know how long this problem has been going on, probably since IE8, but I don't remember when I installed that.
Sometimes certain settings, plugins, BHOs, and so forth that work fine on IE7 can cause problems on an IE8 upgrade, and the IE8 installer misses quite a few of them. The two browsers actually have some significant architectural differences. Going back into IE7 and resetting everything to the defaults, and then re-installing IE8, usually fixes these sorts of problems.
People who installed IE8 RC1 also can have a lot of problems when installing the final release. I usually recommend that they uninstall RC1 before installing the final release.
As an aside, Windows Media Player 11 is another annoyance in this regard, mainly because of all the additional DRM stuff, but also because of various plugins for WMP10 that are incompatible with WMP11. The WMP11 installer is too dumb to recognize them, and they sometimes cause WMP11 to crash within seconds of being started.
When that happens, simply uninstalling WMP 11 doesn't always fix the problem. It can be a real pain. So I recommend that
all WMP plugins (Netflix and other viewers, MusicMatch, DivX and other special codecs, etc.) be uninstalled before upgrading to WMP 11, with a reboot in between just for good measure.
-Rich