What I have found is... I can activate a user on a EXCH2007 server which has HUB/CAS/MBX roles installed fine by pointing the Email profile to this server, but the scenario I am having issues is the HUB/CAS roles are separated from the MBX roles
I have tried the user using email profile pointing to the CAS Server and MBX server, in both cases the device is activated ok - meaning the workplace is created, but no email sync occurs indicating activesync isnt working.