Hi !
I registered just to try to help you with this problem.
I had this same problem and after a loooot of google search and forums, I found how to solve it!!
Go here:
http://www.tweakxp.com/display.aspx?id=841
You will find the answer there, the problem you've said about the "bad files" get solved with just cleaning this value at the regedit.
Check it out! Now my pc works fine, and explorer is no longer 100% when going to avi files.
The only thing is that you have to give up the information windows provides about avi files (duration, bitrate, etc) but it is worth it!
hope I helped a little bit!
bye
faber
ps: sorry for my english, i am from argentina
bye
