Consistently Bad Burns

This seems like such a standard question I almost hesitate to ask but...

Recently I've been having a SHITLOAD of bad burns.  I recently had to back up my extensive mp3 collection to DVD's, so I got started and burned the first disc at 4x (lowest speed my current media will allow) after a fresh reboot, with virtually nothing running in the background whatsoever.  The verify failed about 30% through.  Restarted, tried again, didn't bother verifying.  Tried copying all the mp3's back to my HD to test (figured this would be faster).  At least 11 or 12 of the albums were corrupted.

I wouldn't ask except that this is occurring with frightening regularity.  I have had excellent, fully working burns off this exact spindle of DVD-R's.  I've got a (relatively) new Memorex DVD-9 burner in a 2.5GHz Celeron system.  I have a shitty 256mb of ram, but as I said, I try to be as kind as possible by burning with minimal processes + fresh reboot...

Any tips/tweaks/fucking ANYTHING I can do?  I need to back up around 200+ GB VERY soon due to an odd HDD situation, so quick responses are needed.

>>5
Shit, two strikes--I recently moved my computer to my new apartment, and I'm using two different spindles of DVD-R's, both printable (they were cheap x_x).

I guess I've gotta try firmware upgrade...I don't have the availible cash to buy new DVD-R's since I just blew $50 or so on two spindles of printables, ugh.