Memory leak in 8.0 JDBC driver?

Before I file a bug, I'd like to ask if the problem is known or if I
have done anything wrong.

I am running a database stress test against a PostgreSQL 8.0.3 database
on a Linux machine.
The test program runs on a Windows 2000 client via JDBC, it starts
several threads, each
of which opens a database connection and issues random statements
against the database
until the program is interrupted.

After about 2 hours, the program always dies with an OutOfMemoryError.

I have tried both JRE 1.4.2_02 and 1.5.0_04 from Sun.
I would suspect a programming error on my side, except the same program
on the same machine
runs for days without problems if I run it against other databases
(Derby, Firebird, MySql,
Oracle, MaxDB).

I have got the JDBC3 driver 8.0 Build 312 from
http://jdbc.postgresql.org/download.html,
and I have also tried downloading and building from source.
No matter what I do, memory runs out.

- Should I report this as a bug?
- I did not want to spam the list with the source of my test program,
but I'd happily do
  so if you think it would help.
- Do you have any hints as to how I could debug the problem myself? Can
you recommend a
  memory profiler?

Thank you,
Laurenz Albe