Lost use of webcam upgrading from dapper to edgy.

[Adam Funk]

Under dapper my USB webcam (Logitech Quickcam 4000 Pro) worked in
camorama without any tweaking whatever, but since I upgraded to edgy
all I get is a grey field instead of the image.  The light on the
webcam is on and /dev/video0 is present (with /dev/video symlinked to
it).

Any suggestions for debugging this?

Thanks,
Adam