I'm not sure if this is the right place to post this, but let me know if there's a better one...

I often need to play music while simultaneously ripping a CD, and it had usually worked just fine, but lately my audio playback has been garbled and laden with clicks and noise while using the CD-Rom drive (especially for ripping Audio CDs). This is so bad that the music will slow down to half its regular speed sometimes!

I believe it has to do with the CPU utilization of the CD-Rom drive. I've tried this with a Plextor W4824A drive.

Hmm... I just realized that now the other drive in my computer, a lite-on Combo DVD and CD-RW drive won't show up in windows. Strange.... this must be related.

Would this be a motherboard issue, an ASPI driver problem, or did a drive die and choke the bus? Any ideas?

Does your motherboard have a VIA chipset?

Have you made any system change that might have changed your CD or HD access from DMA to polled? Or that might have changed the priority of your encode (if you are doing rip & encode at once)?

Yes, actually. A VIA KT400, I believe. The gigabyte variety.

Now, I seem to have fixed it, but haven't thoroughly tested.
I think I accidentally partly unplugged my secondary drive
while messing around inside the computer. Who knew that
that would cause so much grief?

A while back this happened, and I could only resolve it
by replacing what I'm guessing was a defective drive.
I tested it under cdspeed, and its CPU utilization was
extremely high and thus I concluded that it affected the
sound when in use because it ate up the CPU completely.

And DonP, none of the above should apply to me...
But does anyone have other ideas?

Not sure if I understand... Have you solved it or not?

If not...
Have had similar problems but with a much older VIA chipset. I could overcome it by either:
a) Disable DMA for the drive
b) Install the "VIA PCI Latency Patch":
http://www.georgebreese.com/net/software/#PCI

Yeah, I think I've fixed it, but just wanted to see what other ideas people have had, because I've had this problem in more than one context.