Problem with GRANT permissions

I have a table called files which is owned by the postgres user. I give
access to hostadm
for INSERT,UPDATE,DELETE to hostadm. Then hostadm does a copy from stdin
using a program
that I wrote in C using libpq. Once this copy occurs, the ACL on the table
files is set so that hostadm
no longer has insert permissions.

PostGreSQL v6.3
Slackware Linux 2.0.0
gcc: 2.7.2
gmake: 3.74
flex: 2.5.4

Matt