1.2b3 can't access camera

[David Evans]

I am having trouble with my QuickCam Pro 4000 camera. When I reboot,  
sometimes the light on the camera will go on, and stay on. When I try  
to use the camera in an application, the application will respond with  
a variation of "the camera is in use."

The camera identifier is blank, says "no cameras."

Even with a fresh restart and no apps running (like IM clients, which  
sometimes take over the videocam at restart), the green light remains  
on, even if I unplug the camera and try different usb ports.

If something is indeed taking over the camera, how do I find out which  
application or process it is?

I've been looking over the Activity Monitor list, nothing pops out as  
obvious. Are there any known process that I should quit or restart?

Running 1.2b3 of your software. I am on a PPC 15" 1.67 GHz Powerbook.

Dave