PT 7 crashing when opening PT 6 projects???

Help! Just upgraded our HD system from ProTools 6 to PT 7.3.1 Running OS 10.4.6 on a G5 (not intel) Trying to open old v. 6 projects and PT crashes. Works like a charm when creating new projects, just won't open old. Am I missing something obvious?? Any help would be greatly appreciated. Thanks, Jen

Very likely this is due to an incompatible plug-in being installed. You should go through your plug-ins folder and either remove or update any incompatible versions. You can use the for comparison.

This may be a plug in problem. 7 is more particular about incompatible plugs then previous versions were, it seems. Mind you the 7-incompatible plug need not actually be instanciated, it can simply be in your plug folder to give instability. Take a good look at your plug folder to rule out incompat plug versions. Maybe even empty the folder of all except a minimal plug in list as a diagnostic step. What happens if you create a blank session and import session data from your 6 session? You might do it in steps, meaning tracks first, then automation, and plugs at the end of the sequence. If you run into a bottleneck, this might point to the problem area. John-

Thank you both for your help - traced it to my v.4 waves plug-ins. Time to upgrade to v.5 I guess. Thanks! Jen