I am running SL 10.6.3 now and have fixed USB support with A DSDT.aml file. The light beside the webcam activates and the camera dropdown for Photobooth shows "Logitech Camera", but I still only have a black display.
The only thing different in system profiler is the current required (mA): which is now set at 500 since it has been recognized.
I know this is posted quite a long time ago but try using Cam-twist for mac and add your webcam. Leave the program on and try using photo booth. This is how my webcam was recognized in photo booth.
Can I have your DSDT if you use one? We have very similar laptops if not exact (mines Dv7 1211-tx with 2.66 ghz and normal DVD drive) because im having trouble with my hardware. random USB start up problems and sound not working.
Hope my info helps.