I have not had any trouble using the plextor premium with firmware version 1.03 and blindwrite 4.5.3. Thats the first thing to check. Second when making the BWA do that at 4X. When you start blindread make sure that extract subcodes is unchecked, I have used max speed without problems. When you start blindwrite look at autoplay support my back-ups have worked with this both checked and unchecked uncheck enhance weak sectors (I haven't needed it) and then start the writing process again I have used max speed without any problems. So far this is the method I used to back-up Unreal 2, UT2K3, Frozen Throne, Black Hawk Down and Viet Cong. I hope this helps you.
if you generate the BWA of the copy is more bad that the original.
Why are you trying to generate a BWA off the copy when you have the original, you can use the same BWA again, just save it and put it in a safe place.