CloneDVD Mobile Lockup Problem

I just downloaded the trial version of CloneDVD Mobile and when I attempt some movies (converting to PSP) the program will lock up mid-conversion. It also locks all other funtions on my PC, which forces a reboot.
I experienced the problem with Sin City but when I tried it again later it worked.
Movies I couldn’t get to complete were Scarface, Saving Private Ryan, Friday, and Raiders of the Lost Ark.
This is very frustrating especially when the vast majority of the conversion works and the lock up occurs with only 2 or 3% of the movie left.
Other than this admittedly large issue, I’m happy with the software, but I’m not going to purchase it unless I can get it fixed.
Has anyone experienced a similar problem? I checked the threads but couldn’t find anyone with this specific issue.
Thanks in advance for any help you can provide!