I've got a plextor 12x10x32, yesterday it developed a proble

the fact that it sees and writes to cdrw discs is not relavent,

there are effectivly 3 laserse in the drive, not literally, i think, but differant specs for the 3 functions, read, write cd and write cdrw

any one of the 3 functions can fail and not affect the other 2

i would say it is faulty, contact plextor, hopefully it is still in warranty