Ok, so I installed a brand new Pioneer DVR-610 (or 110D, whichever you prefer) in my boss's Dual 1.8GHz PowerMac G5 to replace the original writer, which worked but had a lot of trouble reading DVD-R discs. The 610/110D, however -- which was recommended by people on this forum and by companies like OWC for my model of Mac -- won't read *anything*. It shows up in System Profiler, the tray can be open and closed with the keyboard eject key, and I can hear it spinning up when a disc is inserted. But nothing happens. Nothing's mounted on the desktop or in the Finder sidebar; nothing shows up in Disc Utility; and after a minute or two, assuming I leave it in, the tray pops back out, having failed to mount the disc. Hoping a firmware upgrade would solve these problems I used the "DVRFlash 2.2" utility and successfully upgraded from firmware 1.17 to 1.37, but the drive continues to exhibit the same symptoms. I have tested commercial audio CDs, CD-Rs, DVD-Rs, and a CD-RW (all Mac-formatted and verified to work in other G5s in the office). Same results for everything. Apple's FAQ about this sort of thing is of no use; it doesn't appear to have been updated since the OS 9 days, so there's all this stuff about "Extensions" that as far as I can tell don't even apply to OS X. We don't use Classic in the office, and besides, once I figured out which of the 8 bazillion "Extensions" folders they were talking about, I didn't see any difference between the one on my boss's computer and the other G5s.