I checked the C: drive, and instructed the process to fix any errors.
No reported problems.
I then ran ATI again to create another full image. It hung on 0% progress. It didn't give me any reports, and the little revolving arrow icon (that indicates progress) continued to revolve, but it just stayed on 0% for about 15 minutes, until I tried to cancel the whole process. When I did this, ATI hung and I had to crash out.
After I've finished typing this, I'm going to restart and then try running ATI once again. Needless to say, I'm worried!