It looks like my Philips PBDV1640P (OEM) drive has suddenly decided to stop playing ball.
I only got it about six weeks ago, installed it into my main machine (Athlon XP 2400 running Fedora Core 2 and WinXP), upgraded the firmware to 3.2 and it worked like a dream with all the media I threw at it. All of a sudden, last week it seems to start having problems writing 52x CDRs at anything other than 4-5x. I went away for a week, and now I'm back and the drive is refusing to recognise (i.e. that any disc is in the drive) 50% of the -R and +R media I was happily using a couple of weeks ago, and is refusing to write 80% of all discs, including some DVD+RWs I have. Sometimes, I'll put a disc in and it refuses to recognise it, but I'll open and shut the tray and it'll accept it! However it then refuses to burn the disc - it bums out performing the OPC.
The media in question subsequently works completely fine on my wife's burner - an oldish 8x Samsung writer.
So, I've gone from being very happy to very frustrated. I'm taking it back to the shop today and I'll hopefully get a replacement and see how that goes.
(Annoyingly I didn't keep the packaging, but then as it was an OEM drive the packaging only consisted of a thin cardboard shell with some foam padding..)