macaddr stuff !

Hi,
 I have no one to turn to. I've tried here & there but got no answer. Why is there is a problem creating unique indices
onmacaddr columns even if there ARE NO (checked by count on distinct,group by) duplicated keys ?
 
 And finally :
 create table tmac (i int4,mac macaddr); insert int table tmac (i) values (1); insert int table tmac (i) values (2);
insertint table tmac (i) values (3); select * from tmac where mac='01:02:03:04:05:06';
 
 I get backend termination no matter if table has indices, is vacuumed , is new or even just after the postgres
instalation.
 HELP !
 Oh, I use 6.4.2 under i386 Redhat 5.2 Linux.

Pawel Pierscionek,