I've found that sometimes a manual clean of ALL the active x stuff in internet explorer works (you can redownload the controls as needed... flash, shockwave, etc)
"c:\winnt\Downloaded Program Files" is the dir that those things hide, just delete anything you are not familiar with... especailly stuff that is labeled as weird letters and numbers (basically the windows GUID).
Also you may want to manually look at what's in your startup to see if there is something that's loading and hasn't been put into a definition yet.
My fav program to look at what's in your startup
http://www.mlin.net/StartupCPL.shtml