Just make sure that the CamTwist component is gone from /Library/QuickTime and that you've restarted your browser.
Do you have the google talk plugins installed also? You'll have to remove that too.
I understand your frustration but your blame is pointed in the wrong direction. The current version of the flash plugin is broken with respect to being able to select cameras. As soon as your have more than 1 camera to choose from, which would happen if you install CamTwist or google talk extensions (among others), you'll be in trouble.
To fix the problem you'll need to either downgrade the flash player or remove the other camera components from your system.
You can follow the progress of the bug here http://bugs.adobe.com/jira/browse/FP-5730
If you're still having problems, you can email me and I'll help you remove and/or downgrade via iChat.