I found this thread while trying to solve the exact same problem. Since it's been a year ago I don't know if it was solved or not or if anyone will ever see this, but I was able to fix it fairly easily. Here is what I did.
1. make sure the virtual machine is stopped.
2. Under the Virtual Machine Menu select Configure...
3. Scroll down and select "Hard Disk 1"
4. Select "Image File"
5. Re-Select "Boot Camp Partition"
6. Select "OK" and it will ask you if you want to save the changes...
7. Say yes and reboot the virtual machine.
It worked fine for me after this and there was no need to mess with the terminal.
Maybe Charles' problem was different, but I was getting the same error message on startup.
JH
Last edited: Aug 30, 2009