These were the last 2 discs of a 12 disc DVD-R sample pack from Rima. All the discs burned & can be accesssed (as mp3 data discs) just fine except these two 4x Princo's. The first one (in my Plextor 716A) wouldn't finalize (rest of the burn was OK) & the 2nd disc burned great but won't work very well in the same drive that recorded it. I'm trying to copy the DVD back to the hard drive & half of it gives me CRC errors. Not only that but the disc goes up & down in speed. Trust me, I'll never buy Princo media after this bad experience! TY is the only way to go!!! Thankfully I can save some of the MP3 files... Other media in the sample pack was Ritek 4x, Ritek 8x (both burned at 4x & the rest at rated speed), Prodisc 8x, Optodisc 4x & TY both 4 & 8x.