Compact clearly doesn not work right in the release version. The progress bar goes to the complete position and sits there. I tried twice and gave up after more than 24 hours each. This is on a 16GB max dynamic drive that had grown to 10+GB, while internally occupying only 6GB. I had even defragmented prior to trying this. I installed TrueImage 9 - Workstation, and created a second virtual disk of the same size on another hard disk. I then used TrueImage to clone the disk. It automatically copies boot sectors etc., and will only copy active files in the file system - it is not a sector copier. 90 minutes later I was left with a new, 6GB image that worked like a charm. TrueImage does lots of other stuff, and is better than Ghost or similar products. Parallels, your compacting and USB handling need serious attention!
I've used compacting now about 3 times and its worked perfectly for me. Mine was 19GB that I compacted to 5GB. The USB situation does need fixing, though.
It took a VERY long time. This was a 19GB image file that only had 5GB or so used up. It was an image file for my Visual Studio projects, so lots of files. I don't recall how long it took, but I think about 6 hours.
Well, as I mentioned I ttried twice, and gave up after more than 24 hours -I figure, I waited long enough ;-)