General Error driving me nuts.

I received a project originally offline edited in FCE
RED footage converted to 1080p ProRes 8bit

I put it into my FCPstudio 2
took it in to Color color graded it sent it back to FCP
this is where the problems began.
Some clips came back short, some clips came back offset, some came back out of sync, but was able to fix everything by hand, there was no rhythm or reason to the way the clips were messed up. But i just moved on.

Now I am exporting and i keep getting General Error: I have tried exporting a shorter version of the sequence and it is not working i tried half at a time then 1/4 of the sequence and i did finally get a successful export when i went down to about 1/8th of the sequence. But that only worked once and i cant get anything else.
There are no stills in my timeline and I have trashed my prefs just FYI.

Any thought or help on this please?

Mac OS X 10.5.5
2.8 8core Intel
5gig ram
FCPstudio 2 ver 6.0.4

thanks in advanced

Have you tried exporting an EDL and then creating a new project and then sequence from that EDL? Had a whole mass of problems a while back where something in the project had become corrupeted, going via and EDL into a new project solved all problems.