I had something similiar happen to me a while back, but then I realized the difference in batches was because the old one was DVD-R and the new one was DVD+R. My drive was supposed to handle the +R's just fine, but it didn't with these guys. The difference was, it would actually act like it was burning and then just sorta stop at 90% and refuse to move further or quit out. I bought a couple of the old DVD-R's a couple days later and those worked just fine.