Just made the full upgrade yesterday from cs4 to cs5 on windows 7 from vista using the matrox with max. Loving the HD editing. I also tried to open an SD cs4 project in cs5. While opening, and after the message that tells you it is converting to cs5, I got this message - 'The editing mode used by this sequence could not be loaded. The sequence will be opened in desktop mode.' So the project opened, I created a new sequence with the matox settings and cut and pasted the original sequence into it. Any area that had to be rendered went pixelized. The only way I could get rid of this was to remove all colour correction, effects and transitions. When I reintroduced them, I ended up with the same result. I have found a work around, and that is opening a new project and importing the old cs4 project into it rather than just trying to open the cs4 project with cs5. Rather than using matrox settings, I just rerendered the sequence and it works fine, however, I don't have my program monitor which is controled through matrox. This will be the last of two SD projects, but wondered if anyone else had this issue.