Do Exchange 2010 CAS role requires Net TCP Port Sharing service automatic start or not

From the playing around i have done i don't think you can view 2007 mailboxes using CAS2010 unless it proxies to a CAS2007. I have found this which seems to say the same thing:

CAS 2010 can only open 2010 mailboxes; it cannot connect to 2003 and 2007 mailboxes. The only time CAS2010 will do anything OWA related with 2007 is if the user's mailbox lives in a non-internet facing AD site and only has CAS2007 boxes in that AD site. When this happens the CAS2010 box in the Internet facing AD site will proxy to CAS2007, which in turn opens the 2007 mailbox. In this one particular case you'll have to copy the CAS2007 binaries to the CAS2010 server for this to work.

http://social.technet.microsoft.com/Forums/en-US/exchange2010/thread/eeef7ac3-bae0-47d3-be9d-07e62d4c3b92

This also seems to confirm that it can't be done: http://social.technet.microsoft.com/Forums/en-US/exchange2010/thread/96d63d71-c536-4dab-a401-f26c425c29c9

Sorry i couldn't provide a solution.

The error The update does not apply to your system means you already have the update installed, or you are installing a version of the patch for a different Operating System than the one you are running (it might also mean you're trying to install the 32-bit version, but I'm not 100% on that).

Just to double check, you want code.msdn.com and you want the file Windows6.0-KB979744-x64.msu (CBS: Vista/Win2K8).

If you definitely are installing the right update, check out the tail end of C:\Windows\WindowsUpdate.log to see if that gives you any more insight. If you need help trying to decipher it, please edit your original post to include the relevant tail end of the file.