Thank you!
I'm so used to setting that option in explorer on my own machines, I'd for some reason thought I'd already set it via policy for our Domain computers; turns out it wasn't set, and enabling the option to run folder windows in a separate process does indeed resolve the issue (or at least mitigate it to the point where I can't reproduce the hanging anymore). You've made me a very happy man!
Incidentally, you mentioned the only thing you could see in the dump file was a reference to media center; what was the file name that came up? If it's due to a shell extension or service that I can disable I'd like to do that too just to be safe, so any extra information you can provide from that dump file would be very helpful.
Thank you again.