Exchange2003 Public Folder Contact Item disappeared   

We have an Exchange Server 2003 running on W2k3 Server.
There we have different public folders with Customer and Employee Contacts.
And now my Problem, in the public folders disapear Contact Items without
deleting them.
They aren`t there and don't come back. They disappear without opening or
editing them..
Can someone help me please,

regards
Norman

date: Fri, 23 Sep 2005 12:14:52 +0200   author:   Mazda