I am using a 32Gb Transcend card and notice that when it gets about half full nothing records any longer (either video or stills) even though no error message appears. It has been quote disappointing as suddenly the last few items i shot are not there. Reformat the card and it works fine again ... until it gets about half full. Is there is CF card size limit on the 5FMkII?

No there is no size limit that I have come up against. I have a Lexar professional 32GB card and have recorded up to around 20GB on it without reformatting (I haven't had the need to go over that).

I have no problem filling my Transcend 32GB cards.

I have two 32GB Transcend cards that have been in use for a year, no problem filling with either photos or video.

cheers

Morton