Backup won't play on Toshiba

I am completely new to this DVD thing. Although I have been doing quite a bit of reading not only on this site but several others. My first backup attempt seems to be a failure. I used DVD Decrypter, then DVD Shrink. The whole mess fit with a compression of about 92 per cent. I then burned the file to a Fujifilm DVD-R using Nero 6 Demo. My burner is a Plextor PX-708A. The back up works fine playing through the Plextor to my PC but will not load on my Toshiba SD-K610 player. It trys to load but eventually pops up with “check disk”. I’ve successfully copied a friends “Home movies from VHS converted to DVD” disk with no problems using the same Fujifilm disks. Am I missing something along the line here.

My system is a 1.33 AMD with 512 sdram.

Any help or suggestions would be appreciated.