I have had a couple of my sites (3 of them) that have lost their DN programming after a power loss, and One of the site this has happened 2 different times. The really stange thing is that the remainder of the Telephony Programming is still there (buttons, hunt groups, even the name of the Extension sit still there! etc..) and the Call Pilot is all in tact, just the DNs revert to the default DN, we go in and restore the data base and all is good again, but why is this happening? is there a hardware failure or a software patch that is needed