You might want to make sure your Shockwave Flash plug-in is in the correct directory for starters. It should be in...
/Library/Internet Plug-ins/Shockwave Flash-NP PPC
The version of Flash I'm running seems to be stable, 5.0 r56.
You should also make sure you have updated IE to the latest version, 5.1.1.
Then once you have it sort of working, download Omniweb or iCab for a true browser experience. IE is sort of a turd.
You can find them indirectly at versiontracker.com
Hope this helps ya.