Over the last year I've been burning mostly Ritek -R 2x (had problems with the Ritek 4Xs), Fuji +R, TDK -R 4x.

Suddenly today, TDK 2Xs are not recognized by my computer. I've tried Nero, RecordNowDX, DVDDecrypter and ECDC version 6- when I put the disk in the drive all of them say that there's no disk there. I thought it might be a bad disk- so I've tried 10-12 different disks from the pack of 50 (36 of them have burned fine in the past- there's 14 disks left).

Any ideas on what would cause this to happen? I haven't changed or updated any software since the last time one of the TDKs burned (about 2 days ago).