Topfield 5800/Troubleshooting/Playback Interruption
Because you can (normally) copy parts of a recording during playback, the Toppy reserves one of the two recording slots for this purpose, so you can normally record only one other programme during playback. Therefore, to start a second recording it must interrupt your viewing (with a "CYR" prompt) and stop the playback. But this playback can always be resumed immediately (and the system helpfully sets a bookmark to help you do this).
If you are not bothered about copying recordings then the [Xp] PlayNoCYR firmware patch will eliminate the interruptions during playback (with the side-effect of preventing copying of recordings).