Well I have no idea why its working now but it has been behaving OK. What actually happened (now I have double checked the history) was that I did a reload and 3 vim packages needed updating, so along with this I installed jitsi and linphone whicch in turn added a bunch of stuff related to these two packages. Dont see why I needed to update 3 vim package in a separate run, if it had been updating loads of stuff in the system I would have run the update first.
The webcam still seems a bit flaky but I can liove with that for now. At least it's not crashing anymore.
Stuart