table overflow question

All,
I have a script that will fork off x number of process ... each one of these opens a connection to the db polls a different server and polls 200+ mibs. I am doing a update after every poll (so 1 poll (out of 200) then a update.. then another poll and update and so on till 200). So I have 5 db connections each doing a update to the same table but to different rows. Now this works ok. and it work ok if I go up to 10 connections at once.. but any more than that and I get the error "Can't Connect to DB: FATAL 1: cannot open pg_class: File table overflow" now is this to be expected.. or is there some performace tweak I can add.. btw I am running on a hpux 11.11 dual 550 512M.

Thanks,

Travis