unique index

Greetings,

I have a very strange problem that I realy dont now if it should work this
way or if it is a bug or a enviroment problem.

I'm running postgres 8.1.0 on a 'White Box Enterprise release 4' Linux box.

I've created a unique constraint for multiple fields (3) with a condition.
Those fields are: bigint, varchar and varchar and the condition is status =
1 (status is a integer field) .
The condition works fine. It only lets me insert onde possible combination
and if the status condition complies.

The problem is that when I try to insert an duplicate entry for testing I
receive te error (ERROR: duplicate key violates unique constraint
"new_idx_UNIQ") but ALL RECORDS are DELETED. I don't think that this should
happen.

Can any one give me some help on that ?

Regards,
Gus