Sounds like it's either a graphics card driver issue, codec or just plainly a hardware issue.
Can't see why it would be a card driver issue, the tv was working fine & with no software changes anywhere the problem started. Hardware isn't right because the recorded results can be played on VLC perfectly meaning its software/codec really but I have installed every codec upgrade known to man & no change.
I have uninstalled the card programme & driver several times now & reinstalled the latest ones from the Compro site. I have refitted the card in another PCI slot too just in case, even though as I say it was working just fine for several months before this.