I can't say that for 100% of course,but no,I don't believe so.It's a warning that the hash doesn't match,but since I've noticed it in quite a few updates logfiles here,I was thinking it had more to do with some sort of problem with updating,the same way that the bad checksum error usually happened because of a lot of people attempting updates at the same time.All conjecture on my part,I could be wrong,but that's my take on it.
Instead of replacing domains.sbs from another source,it would be better if you downloaded the manual updates and applied them,which should hopefully replace domains.sbs.The manual updates are available under Other downloads on this page:
http://www.safer-networking.org/dl/
For destination,you should navigate to your Spybot S&D 2 folder.Since your two computers are Windows 7 and Windows 8.1,then that path is likely C:\Program Files (x86)\Spybot - Search & Destroy 2\,if they are both 64-bit.