I'm running Ubuntu 10.04 on a Macbook Pro 5.5. When I initially installed, the webcam worked perfectly, and I could use Cheese to take photos or video without any problems. However, now when I open Cheese, it will either freeze when I open it, or show the error "Cannot connect to video device (/dev/video0)". I've tried camorama and fswebcam, but they give me the same error. Rebooting and trying different kernels hasn't fixed it.
What else can I do to diagnose or fix this?
Edit: I reformatted and installed Ubuntu 11.10, but the issue persists. The webcam will work fine one moment, and then apps like Cheese will give me the error "No device found".
Edit: This is a known bug.