StartTransact back at Debug2 in v8?

Dear Gurus,

Please point me to the right way to find the answer, if it's already
answered, and forward the mail to the right list if I missed.

Also, please CC: answers to me, since I'm unsure if I'm subscribed to the
list right now... ;)

In v7.3, our logfiles got bloated by Start/CommitTransactionCommand.

In v7.4, this could be eliminated by a loglevel of DEBUG2, which showed
user-level debug, but not these Start/CommitTransact DEBUG messages.

In 8.0.0rc4 I'm sad to see that not only they are back to the same DEBUG
level (DEBUG2), but it's even more verbose.

Is there a way to configure the log differently, or is there an easy way to
modify the source to do so (e.g. degrading these annoying messages to DEBUG3?

Below is part of my postgresql.conf and a log piece.

TIA,
--
G.

-------- begin postgresql.conf snippet ---------
# - When to Log -

#log_min_messages = notice # Values, in order of decreasing detail:
log_min_messages = debug2

#log_min_error_statement = panic # Values in order of increasing severity:
log_min_error_statement=error

# - What to Log -

#log_connections = false
log_connections = true

#log_line_prefix = '' # e.g. '<%u%%%d> '
log_line_prefix = '%t [%p] %q[%u(at)%d] '
-------- endof postgresql.conf snippet ---------
-------- begin log snippet ---------
2005-01-11 13:52:25 CET [19185] [postgres(at)tir] DEBUG: StartTransaction
2005-01-11 13:52:25 CET [19185] [postgres(at)tir] DEBUG: name: unnamed;
blockState: DEFAULT; state: INPROGR, xid/subid/cid: 2081/1/0,
nestlvl: 1, children: <>
2005-01-11 13:52:25 CET [19185] [postgres(at)tir] DEBUG: CommitTransaction
-------- endof log snippet ---------