I'm attempting to install the product in enhanced mode. This is what I'm seeing from the DMZ box when running the deployment helper. I removed server names from the posts below.
Task Name : Reach EMM Hub Server, Task Result : Failure, Task State : Completed
7/2/2012 9:37:26 PM : Reach EMM Hub Server - Started
7/2/2012 9:37:27 PM : Reach EMM Hub Server - Unable to reach https://XXXXXXXXXXX/emmhub/about.aspx due to Unable to connect to the remote server
7/2/2012 9:37:27 PM : Reach EMM Hub Server - EMM Hub doesn't seem to be installed in the given EMM Server.
7/2/2012 9:37:27 PM : Reach EMM Hub Server - Finished
The EMM Hub is installed on the internal network so I'm not sure why it isn't able to see it. Connectivity appears ok or I doubt I would be seeing this type of message.
Have you disabled windows firewall? Is your proxy in the DMZ with a firewall between them?