Hello drglenh
If you have really tried every possible solution, see your Apple-Authorized Service Provider for a hardware fix.
Have you tried every relevant suggestion in
How to Troubleshoot iSight?
iSight drivers are in all Combo Updates, including Tiger's latest for your MacBook Pro:
Mac OS X 10.4.11 Combo Update (Intel)
Repair permissions before AND immediately after running the updater.
QuickTime Pro works great for me. If you think QT may be a problem, reinstalling
the latest QuickTime might help. I suggest permissions repair before and after.
EZ
Jim
PowerBook 1.67 GHz w/Mac OS X (10.4.11) G5 DP 1.8 w/Mac OS X (10.5.1) External iSight