I have a Sony DVP NS300...... I have made about ten backups which ahve all worked just fine. For some reason, the last two are fine until it really gets into the movie (30minutes). Then HUGE blocks appear over all movement. these blocks about 1/2 inch on each side and cover everything. This doesnt happen on any of the computers I have played it on, and i am using the same discs I ahve been from the beginning. I have gone as far as burning the entire movie on three different discs and lowered burn speeds, all with the same results. Any suggestions???