[G4] One processor cuts out

[Laura Webb]

I've had an odd thing happen a few times, that I've noticed anyway.
My computer slows down and when I check the Activity Monitor,
only one processor is functioning. I restart, everything is back
to normal, both processors functioning. Any ideas as to what is going on?
The only recent addition is a OWC sata card w/ a Maxtor 500gb internal
attached. Also, since installing the card and drive, my audio is a bit
messed up, cutting out, and switching from int. to ext. Could both problems
be related?

Dual 1ghz quicksilver
1.5 gb ram
OWC sata card - 1 int. drive
2 other ide ata drives (200gb + 120gb)
Firewire card
9800 Radeon 
Mac OS X (10.4.8)

Thanks in advance for any help,
Laura