Some seriously weird problems..

First off, I have successfully burned 17 DC titles but am having problems with the following games (all self-boot Echelon releases):

Starlancer
18 Wheeler
Prince of Persia
NFL Blitz 2001
Vampire Chronicles

They seem to burn fine but do not play in the DC. I was using DJ3 and had many successful burns w/ 17 other titles but not w/ the ones in the list. I downgraded to DJ2 to burn the above games again but still no luck. Now that I'm using DJ2, it forces my recorder to burn at 1X (I got a SCSI Plextor 12/10/32). Can anyone help me with this problem? With DJ3 I could burn at 12X. Why does everyone say to use DJ2?