Assuming it also shows signals on both tuners.
What has happened in the past is one of the broadcasters with multiple regions can screw up the programme series identification codes (CRID’s) which can cause the unit to try and also record other regions at the same time. You should be also to see this on the guide if you page backwards to the channels > 950.
If you ignore the message, then by default, the unit will take you to one of the two channels it is trying to record.
What can cause conflicts is programme overruns and this can also occur if start and/or end padding is set.
Sorry but no real idea re the disk full problem – My guess is there was a write problem to the disk which was interpreted, in error, to be a disk full condition.