group by bug in 6.2.1 & 6.3 -snapshot

Hi

I find next bug:
in query "select a,b,count(*) from q group by a,b;" postgres do:
a	,b	,count(*)
5	2	3	???
5	2	2	???
6	3	6
.................

table - about 10000-30000 tuples.

PS: i use linux 2.0.33 & solaris 2.5.1

-- 
SY, Serj