My plugin list is
QuickTime 6.5.1
Shockwave Flash 7.0 r19
Java 1.4.2-3
Acrobat Reader
I haven't had any trouble with web sites not working with Mozilla. If anything some work better on some systems than with IE (ESPN comes to mind).
However, it is possible to have a web site detect IE vs. other browser and fail for others. Opera has a way to fix this by claiming to be IE so thst the web site sends good HTML.
One other trick: a *lot* of web sites send WMV files with a bad content-type: they claim to be sending a text file, so Mozilla displays text. IE has a bug and shows the video - probably what the user wanted, but not what the web site said, it will cause problems in other cases. Just save the file to disk and then play it there, and complain to the webmaster.
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"If they can't picture me with a knife, forcing them to strip in an alley, I don't want any part of it. It's humiliating." - windsock