I am getting the exact same thing! It is pissing me off! I mean I have CloneDVD2 also and when I try to burn the DVD files that I created using DVDSanta there is always and error using CloneDVD2 too. I am thinking it has something to do with the actual files that DVDSanta is creating maybe? I need help cause it really is making me mad, good thing I am using +RW.
My experience has been that unlike other programs, DVDSanta would continue to 'encode' when an error is encountered. The result is of course a bad copy. So it's very important to check the integrity of the original file(s) before burning with DVDSanta, even more so if e.g. the avis were downloaded.