@RRRR I'm using a 32gb Sandisk 30mbps. So maybe the card is not fast enough and its going into fall-back mode? I'm sticking with mpgxsvcd's 40mbps hack for now :)

@Jrb it should be fast enough if the card is formatted in-camera in between patching.. if you get similar results, try doing a Low level format (do a one pass or 7-pass format in osx) to see if the performance improves.. If you look around the forum I'm sure you can find topics about card performance - there was a thread recently where someone linked formatting software that should help get the best out of your card.

Really, you should be able to use better quality patches than the 40mbps one (without issues). I use that one only for long takes - where IQ is secondary to reliability.