Kevin any update here. Started to edit a feature shot on Canon 5D Mark II with the footage as .mov h264 files and have run into the same problem documented in this thread. Files do not play in PP 5.5, DSL 1080p 24 setup! Setup the same project in PP 5.0 and the media plays fine. I noticed this tread is dates Aug 2011 and it is now Feb 2012 so I am hoping there is a solution but fear there is not. I made the move from FCP 7 after the FCP X release to PP looking for a DS workflow but I am nervous now that I made the wrong choice.
Also purchased the Matrox MXO2 w/Max and cant seem to get it up and running with PP 5.5 when it running smooth plug and play with FCP 7.0
If Adobe is serious about capturing a fleeing FCP user base with PP 5.5 things need to get better.