Guvcview used to work for me, but now when I open it the preview and any photos taken appear to have a green filter over them. Or maybe like the blue and red channels have separated a little, because in some images you can see a faint blue outline of the object below it and a faint yellow outline of the object above it.
The webcam works fine in the browser and in other applications (i've only really tested cheese), so I don't think the problem is with my webcam.
I've attached two pictures, one taken with guvcview and the other taken with cheese.