[Dclug] Hangs

[Navy Dragon]

I've been experiencing some annoyances lately when my computer is
under heavy loads.  Frequently, when the CPU is at 100%, then my
entire system (at least under XFCE) sporadically hangs for a second or
two.  I'm not 100% sure, but I think this started happening once I
added an additional 2GB of memory to my existing 2GB.  Here is the
output of uname -srvmpio:

Linux 2.6.22-gentoo-r8 #1 SMP Sun Oct 28 18:57:18 EDT 2007 x86_64 AMD
Athlon(tm) 64 X2 Dual Core Processor 4200+ AuthenticAMD GNU/Linux

I was wondering if maybe there is some particular setting or something
I can do to improve responsiveness while under heavy loads?  I tried
compiling a new kernel recently that had the options PREEMPT_VOLUNTARY
and PREEMPT_BKL both turned on.  From what I could gather, these
options are supposed to improve responsiveness on desktop systems (of
which mine is), however they seemed to have little effect.

Any advice would be greatly appreciated.

TIA