After first having trouble to get the SP1 install to work at all (see this thread: http://forums.microsoft.com/TechNet/ShowPost.aspx?PostID=2495133&SiteID=17), I now have a new, even bigger challenge. During the SP1 installation the HubTransportRole update finishes, but next is the ClientAccessRole and here, the installation fails with the following error: This role cannot be installed because the following roles are not current: MailboxRole Anybody has an idea how to fix this? My Outlook Web Access is not working anymore because of this...

OK, I got everything to work. The way I fixed this, is the following: 1. I removed the Client Access Role 2. I manually started the upgrade process again through the command line: Setup.com /mode:Upgrade 3. I re-added the Client Access Role I still think it's weird I received this error in the first place. During SP1 installation the Mailbox Role is upgrade after the Client Access Role. And the error I received during Client Access Role upgrade mentions my Mailbox Role is not up-to-date