Bad sound with AC97 and AMD 64 X2 (Gigabyte K8N Pro SLI)

[Dan Hensley]

I just built a new system using the components in my subject line.  The
motherboard has built-in sound chip using the ALC850 CODEC.  I also have
an nVidia 6600GT.

Installation of FC4 x86_64 went fine, and all my hardware was auto
detected.  However, I noticed some strange behavior.  When the CPU was
busy, either with compiling something or running up2date (there have
been a LOT of updates since the distro was released), several things
happened.  My keyboard was acting up--one keypress would produce several
characters, making typing impossible.  And my clock would gain lots of
time--up to 10-15 extra minutes in a 30 minute period.  I also noticed
that my sound was pretty bad--Wesnoth music was choppy, and sound
effects were delayed and some didn't play.  I looked at dmesg and saw a
message saying something to the effect of a driver hogging interrupts or
an "instable (sic)" clock source.  I'm using NTP for my clock sync.

So I disabled AC97 in the bios, and these issues went away.  I
re-enabled it, and my video settings went back to default for some
reason (editing xorg.conf fixed this).  Now sound is still pretty bad,
and my clock is still gaining time, but I haven't gotten the hogging
interrupts message again.

I also noticed another message from dmesg:

application mixer_applet2 uses obsolete OSS audio interface

Does anyone have any idea what's going on?  Is this a motherboard
problem?  BIOS?  kernel?  audio driver?  Any suggestions on how to fix
this?

Thanks,
Dan