insufficient data left in message

This is a postgresql 8.2.5 backend. connected to a jdbc client.

2008-02-21 06:12:30 EST [18880] 10.21.0.21 ERROR: insufficient data
left in message
2008-02-21 06:12:30 EST [18880] 10.21.0.21 STATEMENT: select * from
user_profile,user_profile_access where user_profile.uid=user_profile_a
ccess.uid and user_profile.uid=$1 and isactive=$2
2008-02-21 06:12:30 EST [18880] 10.21.0.21 FATAL: invalid frontend
message type 0

This is repeatable, but not 100 percent of the time.

So the question is: how to go about debugging this ?

Dave