I would try to enable diagnostic logging for access control on your pf, and see if you notice anything unusual around the time of when it disappears again. James Chong (MVP) MCSE | M+, S+, MCTS, Security+ msexchangetips.blogspot.com ________________________________ From: exchangelist-bounce@xxxxxxxxxxxxx [mailto:exchangelist-bounce@xxxxxxxxxxxxx] On Behalf Of Mark Morgan Sent: Thursday, August 09, 2007 4:07 PM To: exchangelist@xxxxxxxxxxxxx Subject: [ExchangeList] Public Folder Calendar events Disappears Hello Everyone, I am having a strange problem, I have Ex 2003 on windows 2003 latest updates and patches. every few days all the events in our public folder calendar disappears and I have to restore from a backup. Has anyone ever run across this issue and does anyone have any idea what could be causing this to occur? Thank You Mark J Morgan No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.476 / Virus Database: 269.11.8/941 - Release Date: 8/7/2007 4:06 PM No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.476 / Virus Database: 269.11.8/941 - Release Date: 8/7/2007 4:06 PM