An apt-get dist-upgrade (to bring the kernel up to date and install some new patches) on the slugs killed the webcam. Of course I should have remembered that the gspca module was built against the old kernel and might fail. One quick “m-a auto-install gspca” later and all is working again.
Of course the kernel update required a reboot so my uptime is now back to zero, but security is more important than a long running time.