Divx to DVDr - CM's Guide

can anyone help me out? I have been using CM’s guide converting XVID and DivX to DVDr with no problems until I recently had to reinstall XP. The problem I am having now is:-

After the CCE bit, BBmpeg kicks in and just as it’s coming to an end it gives an error ‘cannot write to output file’. My first assumption was that I was running low on HD space, and I know CM does recommend 20gb free but I have converted loads with only 15gb free and it has only happened recently since the reinstall???

According to the guide, this method does not use BBmpeg so I am confused. I have been over the settings a few times but can’t see the fault. If anyone can help I’d appreciate it.