I upgraded my main hard drive which had a bootcamp partition on it. I made a DMG of the boot camp partition and then later restored it on a new partition (on the new drive) using Boot Camp Assistant.
Now all of the files are there but it is not bootable. When I press Option upon boot, I'm only presented with my main partition.
I followed the instructions here: http://discussions.apple.com/thread.jspa?messageID=10835653
which basically said, use fdisk to flag the partition as bootable, but it seemed to have no effect.