Ah.. I didn't even realize you could select a webcam from the scanner page.
So let me ask, if you manually trigger a "Scanner" capture, after having configured your webcam as the "scanner" device, does it capture from the webcam? If so, i can fix the Auto Capture Timer thing.
Additionally, you might want to check out my Webcam Video Diary
application, as it also has some timed capturing options and is specifically made for webcams.