Just checked the tech specs of 12 and found the following:
Container: Multiple streams of binary data totaling no more then 4 gigabytes per container field. (new storage types added)
There is no other specification given on externally stored container fields so I presume this applies to both internally and externally stored?
Can you download the DMG for a small application and try that? Perhaps FireFox for Mac?
Ben, thanks for the suggestion. I uploaded a Skpe DMG since it was only 34 megs and it uploaded just fine to the container field. Maybe it is a size thing because the FMP12 DMG is almost a half a gig. I wonder if anyone knows the size limit or any ways around it.