postmaster(s) have high load average

I have one process which writes a single float into 300 columns once per
second. I then run 4 process, from remote computers, to query a small
subset of the latest row.

I have even commented out everything in the query programs, all they do
is sleep, and the associated postmaster still sucks up 15% - 20% CPU.

Computer is a P4 /w 1Gig memory, all disk access is local. RH9 /w stock
postgresql-7.3 installed.

I have searched the documentation and tech site high and low for ideas....

17:36:27 up 31 days, 6:07, 13 users, load average: 4.11, 2.48, 1.62
107 processes: 99 sleeping, 8 running, 0 zombie, 0 stopped
CPU states: 22.3% user 76.0% system 0.0% nice 0.0% iowait 1.5% idle
Mem: 1030408k av, 976792k used, 53616k free, 0k shrd, 178704k
buff
715252k actv, 33360k in_d, 22348k in_c
Swap: 2048248k av, 91308k used, 1956940k free 589572k
cached

PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME CPU COMMAND
23389 cjw 16 0 2896 2752 2132 R 18.2 0.2 0:44 0 postmaster
23388 cjw 16 0 2896 2752 2132 S 18.0 0.2 0:45 0 postmaster
23391 cjw 16 0 2896 2752 2132 S 18.0 0.2 0:43 0 postmaster
23366 cjw 16 0 3788 3644 2560 S 17.8 0.3 2:32 0 postmaster
23392 cjw 16 0 2896 2752 2132 R 16.2 0.2 0:05 0 postmaster

--
--Chris

How is it one careless match can start a forest fire, but it takes a
whole box to start a campfire?