We have 3 2007 exchange servers needing to be upgraded to SP1 we have 1 HTS server and 2 mailbox servers in ccr mode witch order do we install the upgrade? do we start with the HTS role server or do the mail box servers first i cant find anything on the net about this thanks in advance

Check out the release noteshttp://download.microsoft.com/download/5/e/6/5e672458-592a-44a2-b489-11cec19d3c82/RelNotes.htm"We recommend that you upgrade your servers that are running the Mailbox server role after you upgrade your servers that are running the Client Access, Unified Messaging, Hub Transport, or Edge Transport server roles. If you upgrade your servers in this order, you may avoid potential service interruptions."