Hung backends

Hi,

I'm new to PostgreSQL and have been tasked with determining the cause of
hung processes on FreeBSD after the frontend app dies. Eventually we run out
of connections when hung processes = MAXBACKENDS.

ps -cl -U postgres returns:

UID   PID  PPID CPU PRI NI   VSZ  RSS WCHAN  STAT  TT       TIME COMMAND
  500  1395     1   0   2  0  4040 2380 select Ss    ??    0:01.17 postgres
  500  2255  1395   0   2  0  4384 2984 sbwait I     ??    0:00.01 postgres
  500  2256  1395   0   2  0  4384 2984 sbwait I     ??    0:00.01 postgres
  500  2257  1395   0   2  0  4384 2984 sbwait I     ??    0:00.01 postgres
  500  2258  1395   0   2  0  4384 2984 sbwait I     ??    0:00.01 postgres
  500  2259  1395   0   2  0  4384 2984 sbwait I     ??    0:00.01 postgres
  ...

The java frontend I'm using to test this scenario makes multiple connections
and crashes(unhandled exception) before disconnecting. This appears to leave
one "postgres" proccess for each connection. Can anyone point me in the
right direction?
SELECT version(); ->  PostgreSQL 7.0.2 on i386-unknown-freebsdelf4.0

Thanks for any advice.
Peter Schmidt