I did untick the one on the main page as well. Then when it didn't remember it I went through all the options to find if there was another tick box for it.
Under the Write tab in Options there is "Verify against Image file"
Yes, the others were in the Synchronise section.
I'll have a check on other settings on this machine, maybe something that's been set up to keep the system clear is causing issues.
Thanks for the swift responses, and keep up the great work Lightning, I've been using programs of yours since early DVDDecrypter.