Bwa every time different?

I tried to burn gothic2 using the instructions or UT2k3, because Gothic2 uses the newst securom, same as aquanox2 and probably also far west. The first 2 Cd´s worked fine, but the third is making me problems. I once tried to make a bwa of the CD using my toshiba DVDrom drive and once using a YAMAHA 241040. the bwa files of both were quite different. Can anyone tell me with what file I should make bwa´s, I heard you can also try to make one woth alcohol and then convert it to bwa. What other possibilities do I have, should I give twinpeaks a try?

Oh, and btw, must I always make a bwa file for games using the newest securom, especially with the new blindwrite?