Yes, I find this super-annoying. And the scanner is not smart enough to coninue from the last point where it was interrupted if you need to shut down, so in my case it NEVER completes. Well, untill I search my system for all *.iso and *.img files, and add them to the exclusion list one-by-one (wild-card support for filenames would be great).
This part of the program's functionality can do with some much-needed improvement.
BitFlipper