BLIND as a bat, thanks HOOD.
What version are you running. We have seen problems with large files in later versions of mach. I have a simple 5mb test file that can Make mach cry UNCLE every time. It has also been know to crash MACH all the way out to a dead computer. ALMOST like mach had a MEM leak and would corrupt itself. Still looking for that one.
Does not seem to happen with V.019.
I think we need to do some more documented testing with large files ,there MAY be a problem that needs FIXIN.
Just a thought, (;-) TP