loosing 1/4 > 1/5 frame when processing in C1Pro 3.7

Hello gang,

Here's my dilemma:
I rotate a Canon 5D RAW (from drive, not camera) to vertical in C1...make it pretty...cropping is off...scaling is at 100%...save as tiff...and hit process image.
It does its thing, but the tiff that opens in PS CS3 - has somehow been cropped by around 20 > 25%!

This didn't used to happen, and I can't find any reference to such a "large" crop issue anywhere on this forum. C1 is turning a 2912 x 4368 px, into a 2171 x 3632 px size...somehow.

Yes - I must be doing something wrong...but what is it?
Make me feel stupid - show me the error of my ways!!

Thanks,
kng