Bug: Arithmetic Overflow

[hexac]

Hello

This is the second time now that file scanning is interrupted due to this bug.
I had never used your software before. It is scanning four hard drives of mine.
I have tried twice: the first time, I was using SHA-512. Now, it's been set to MD5.
Scanning takes about 30 hours and gets interrupted by this error.
I have not found any log files.

Here's a picture: https://www.dropbox.com/s/71jn2o5a8dyp80b/bug.png?dl=0

What can I do?

[hexac]

By the way, scanning takes too long. You should think about optimization.
My machine should take less than 1/4 the time it is taking.
I am programming my own now, I just want a list of files anyway. :d

Nice program, though.

[DigitalVolcano]

Thanks, looking into this - probably a rogue integer somewhere.