G0ROZ-3 Stopped again.

G0ROZ-3 vanished from the map yesterday afternoon (11 March 2015). aprs.fi shows that the last beacon was sent around midday(ish).
I visited site today and found the computer had stopped working with an error message to say that it could not open the COM port as it is already in use.
This is usually caused by a electricity supply interruption, where the computer loses power but it comes back on again before the machine has time to close down properly.
A quick re-boot and all is well again.
I did take the opportunity to disable the desktop clean-up app, so that should not cause any more problems.