buffers don't shrink

[Tom Vier <thomassr@erols.com>]

i have a PWS 500a miata, and i've noticed that after about a week of uptime,
i have almost 400megs (out of 512) of ram used up by buffers, forcing other
pages out to swap. what exactly is the buffer space used for? i assume
"cache" is FS cache. has anyone else seen this behavior?

here's the output of vmstat:
   procs                      memory    swap          io     system         cpu
 r  b  w   swpd   free   buff  cache  si  so    bi    bo   in    cs  us  sy  id
 0  0  0   1000  26952 382624  58056   0   0     1     1    3     6   4   2   3

-- 
Tom Vier <thomassr@erols.com>
DSA Key id 0x27371A2C