Just done an apt-get update and apt-get upgrade
Web-cam borked again
If I issues the command:
lsusb
After hanging for 30 seconds or more, it eventually provides a list which includes the web-cam. At which point, if I open Cheese it will then work.
However, as before, half the time I issues the lsusb command, it just hangs and never provides the list of usb devices (or, at least, not after waiting a minute or two and so necessitating me killing the terminal)