Have to admit I have had a couple of "issues" when I was playing GT5 and PlayTV was meant to be recording something. There was a recent update for PlayTV to take it to v2.00,and that's when I first noticed it not recording. However since the latest update of v2.02 this doesn't seem to have happened again. It wasn't everytime, only once or twice which annoyed my girlfriend as the programmes were for her.
Might be worth deleting all PlayTV data from your PS3 and doing a full reinstall.