to_timestamp() and quarters

Hello.

I can't seem to get to_timestamp() or to_date() to work with quarters, 
can anyone see what I'm doing wrong?

e.g.
	select to_date('2010-1', 'YYYY-Q');
	Gives "2010-01-01" (correct).

	select to_date('2010-3', 'YYYY-Q');
	Also gives "2010-01-01" (should be 2010-07-01);

Am I misunderstanding how this function works? EXTRACT(QUARTER FROM 
date) works fine.

I'm running Postgresql 8.4.2 on a FreeBSD system.


Thanks,
Asher.