Color is doing unwanted croping on my video,....

Hi there, I'm experiencing some weird problem when running color documents. I have a "main" computer (G5 2,5GHZ + 2,5RAM 256 graphics) where I usually work, no problems there. I also own an intel imac.

So the problem begins here... yesterday I was kind of in a hurry and needed to render a 30 minute edit that was already graded. So I thought, well, I'm making a copy of the color file and i'm using the imac for rendering small sequences over the network.

I opened the color document on the imac, it automatically reconected the files from my G5, but the graded image appeared cropped maybe 75%. I hit play and even though it was cropped, it ran well. So i figured it was a network issue. So I started rendering...

When it was done..SURPRISE!! all of my rendered material from the iMac was cropped 75%. I rushed to render on my G5 and finished the work, but I keep wondering what happend??

Any ideas???