Pioneer DV-696AV playback question (noob)

[Bobsen]

Hi all,
I recently purchased this Pioneer player (Dec 2006) and have been very happy with it until recently when sometimes (but not all) the playback with start with a half screen (the screen on the tv shows the top half in the middle of the screen). This can only be corrected by turning the player off and then on again, then it plays ok.
Is this just a minor thing or an indication of a problem that the warranty would cover?
Also, 'skipping' or slowing down frame by frame in certain parts of playback on a otherwise new and 'clean' disk, doesn't necessarily mean it is the player right?
It could just be a fault in the disk? It is the series 'Battlestar Galatica' series two disk three, PAL, all the previous ones worked fine.
Thanks in advance,
Bobsen