Inifinite socket send from backend to java servlet

I'm running RH Linux 5.2, Jdk 1.1.7v3 on machine A, and RH Linux 6.1,
postgres 6.5.2 on machine B. Some queries made from A to B never return. It
looks like the java servlet on machine A skipped out on the query or the
thread died or got interrupted or something, and machine B is infinitely
waiting for it to read query results. Doing a ps -x will show several
postmaster processes doing SELECT's, but just sitting there, ( not SELECT
waiting), but not consuming any cpu time either. When I restart the web
server on machine A and then immediately look at the postgres log file on
machine B, I get a ton of these messages...

FATAL: pq_endmessage failed: errno=32
pq_flush: send() failed: Broken pipe

Within a half day or so, my database connection pool is exhausted because
there taken up by these infinite waits. Of course, I could write a db
connection timeout thread that closes these lazy connections, and I suspect
that the postmaster processes on machine B would detect the broken
connection and go away also, but still... seems like pretty icky behavior.
Any comments?
Rich