I just got a Lite-On 166S to replace my old DVD-ROM that didn't do too well at reading the burns from my 2500a. kprobe scans showed nice P1 levels, but there was a consistent p0 error of 1 in every block tested. So I go to the JLMS site to flash to the latest firmware, and after a successful flash my P1s are in the 700s, and my P0s can get up to 200 before kprobe just stops reading the disc. Nero stops the speed test after a few seconds with "circ unrecovered error". But the funny thing about all this is that the data off the discs seems fine. It copies at 7-8x, and the files I've tested checksum correctly. CD reading seems unaffected. However, reading DVDs makes a high-pitched whining sound that I'm pretty sure it didn't make before. Flashing it back to its stock firmware didn't fix it.
So did I kill it? I'm still not even sure what's really wrong with it. Puzzling indeed.