I've got a weird situation going on. I had an old Arch DVD and it's SHA1SUM checked fine with the one on the Arch website, so I used it to re-install the system. Then I grabbed my 2 DVD+RW's I have and erased them completely. Both DVD's are equal, both are from the same brand (Sony) and bought the same day from the same store. I used the first DVD to burn the newst Arch ISO, and the SHA1SUM checked fine. Then I burned openSUSE Leap 42.1 on the second DVD, and now the SHA256SUM doesn't check. I tried K3B and xfburn, tried quick and long erases, tried even installing openSUSE before burning the DVD, and nothing. It's interesting because the SHA256SUM on my /home folder checks with the real SUM, and K3B tells me the correct MD5 before burning.... but after burning nothing checks out. Does anyone have an idea of what it could be? I'll try burning Arch on the 2nd DVD to see if it is the problem.