Hmm...
When using an INTEL-CAM, the author of the driver suggests you use an aditional parameter usbgrabber=1 (if it has a id 0x733:0x430). Did you try doing that ?
Well, in any case, I'm posting my latest binaries here if anyone wants to try them. There are 2 modules, the regular usbvideo.o, and spca.o which has both spca5xx and spcadecoder modules together. The driver does include debugging, and spits a lot of stuff into syslog.
cheers