No, I hadn't tried the acpi=off on the boot line but I was using pci=noacpi. Figured that would get the acpi issues out of the way but .... it apparently didn't. I just rebooted with acpi=off switch and you were absolutely right - the system now appears to run ok.
I had upgraded to ALSA 0.9.5 and was having the same issues as with 0.9.4.
Clearly, the problem is the new acpi code in the kernel and it's interaction with the hardware. I'll just go ahead and change from pci=noacpi to acpi=off on the boot line.
Thanks for the response and help.