[horde] Horde says: "Empty result." when user not found in LDAP

[Silver Salonen]

Hi.

I'm using LDAP to authenticate users. I bind with a special user done for 
Horde. When I try to login with an existing user and I set a wrong password, 
I get "Login failed." error. But when I try to login with an non-existing 
user, I get "Empty result." error.

How do I say to Horde it should always say "Login failed."?

Thanks,
Silver