Firstly, great program. I recovered some files after my MBR became corrupt, although I could only manage to get text files. Anything sizeable was corrupted.
Anyways, I was running a deep scan on my 500GB HDD and it took about 12hrs in total. However I did manage to accidentally quit the first attempt at the scan about 4 hours into it because I accidentally clicked on the "Cancel" button while I was closing a windowed internet browser.
I would suggest a confirmation text, so that when you click "Cancel", you are prompted with a dialogue box displaying "Are you sure you want to q