I'm currently running Exchange 2010 SP1 Rollup 1. i have a multiserver, 2 of each exchange roll. I have Bes 5, Unity 7, Outlook 2010, 2007, 2003 systems all accessing this exchange system and everything is working fine until i installed Exchange 2010 sp1 Rollup 2. After installing that update on my CAS servers (setup in a CAS array using NLB), Bes5, Unity 7, as well as my exchange 2003 clients are no longer working. Basically the mapi profile can no longer connect to the exchange system. if i go into the mapi settings and try to do a check name, it instantly tells me that there's no server. So to fix this issue, i removed the Rollup 2 reboot the cas systems, and everything started working again, i'm able to go into the mapi profile and do a check name and everything underlines as it should. But this is only temporary...intermittenly - down the line, if i end up rebooting the CAS system again, the problem re appears, and this time without having Rollup 2 installed!! I've found a work around for it, but its really not a satisfactory work around. The work around is to install Rollup 2 again, reboot the system, then uninstall rollup 2, reboot the system, then everything starts working again. I dotn see any errors in the event log, and i dont understand why this is creeping back up even when Rollup 2 is not installed now. How can i make this stop.