2008 MacBook random pauses

Hey there,
I recently purchased a supposedly refurbished MacBook off Craigslist. (I'd spilled a glass of water on my previous one, which worked for years without any issues). I've noticed that it will often just pause randomly, for only a fraction of a second. This isn't that big of a deal, except that I also use my computer for audio recording, and these random pauses obviously become frustrating. I've repaired the disk permissions, as well as verified the disk. Disk utility says the drive appears to be ok. And it also doesn't seem to matter what programs or how many I have open: I can just be running Safari, or Pages, and these little pauses still happen...
Any ideas?
Thanks,
-Ryan

Page outs and swap used both say "0 bytes."... I'll try out one of those programs you suggested, thanks for your help!

Xbench score... what does it mean?

So, I downloaded and ran Xbench, and I got an overall score of 74.73...

Xbench HDD test results.

Ok, here's just the disk test results:

Results 60.50
System Info
Xbench Version 1.3
System Version 10.6.8 (10K549)
Physical RAM 4096 MB
Model MacBook3,1
Drive Type WDC WD2500BEVT-22A23T0
Disk Test 60.50
Sequential 90.01
Uncached Write 132.51 81.36 MB/sec [4K blocks]
Uncached Write 105.10 59.47 MB/sec [256K blocks]
Uncached Read 47.66 13.95 MB/sec [4K blocks]
Uncached Read 156.32 78.57 MB/sec [256K blocks]
Random 45.56
Uncached Write 18.46 1.95 MB/sec [4K blocks]
Uncached Write 110.92 35.51 MB/sec [256K blocks]
Uncached Read 61.37 0.43 MB/sec [4K blocks]
Uncached Read 120.36 22.33 MB/sec [256K blocks]

Hopefully this is what you're looking for.