Just to add another failure story:
I purchased 2 of the PNY 50pk 700MB from BestBuy about 6mo's ago when they were on special (after rebate). The media I purchased is definitely crap. The first CDR I took out, when I looked at it from the bottom, had a part of the dye missing (you could clearly see a hole in the surface area). The hole was near the outside edge so I just burned a cd that didn't go to the edge... and it worked fine.
I then checked out other discs and some of them have a wavy / warped appearance that is DIFFERENT than what I'm used to seeing. It looks as though the tracks are not perfectly round. The disc itself is flat, just the tracks don't look right. Some still burn ok, but:
All in all, I've had about 5-10 failures from this 50pk. Ranging from burn failures to problems reading the successful burns on various CDROMS. This is definitely a media problem as I have not had one problem using any other media on my Yamaha 6x4x16 SCSI, even now.
As always, Your mileage may vary.