blanking CD hangs my system

As long as a thread on CD burners has been started ...

I have a Plextor Plexwriter PX-W8432/SW CD-RW burner.
It worked fine for quite a while. I use it for system
backups.

Suddenly, whenever I try to blank a CD-RW disk, the
system hangs flat, 100% of the time.

The backup script I wrote first makes the ISO image of
selected files, then blanks the disk, then records.
During the blanking sequence it runs fine until the
very end, when it's doing some sort of finalizing
magic, at which point the system behaves like it hit a
brick wall. There is no response to any keys, and I
can't get to it from the Net. The only way to recover
the system is to press the reset button.

Needless to say, this is not pleasant, and is not
characteristic of Linux.

I hadn't even tried this for quite some time (which
means that I haven't been doing backups). Last week I
thought I'd give it another spin in case something
miraculsouly healed itself. It hadn't. Bang! Ticked me
off, because I hadn't rebooted the system since
mid-Novemeber, even through all the home.com => cox.net
transition.

My guess is that I may have done something screwy to
the drivers last time I rebuilt the kernel, but I can't
imagine what. I'm able to mount and unmount CD-RW disks
that are good, and I'm able to make ordinary CDs.

Does anyone have a clue how I might investigate this
problem further?

--
Lynn David Newton
Phoenix, AZ