TBS6983

Just installed a TBS6983 on a Windows 7 x64 PC. I have been able to do a blindscan and found all the channels I expected. Some channels are fine using DVB Dream, however some channels have a problem with picture and sound breaking up. I think it is a codec issue or a video rendering issue. Please could someone let me know the best codecs and rendering mode to use with this card and using DVB Dream?