Push install hangs at "In Progress" on SBS Essentials

Has anyone successfully used SBS Essentials 2011 to push installs to Win7 64-bit clients? If so, did you have to adjust the firewall on either the server or the client or both?

I have two SBS Essentials networks with this same issue. Target clients pass diagnostics (only with WFW off) but push hangs with either "In Progress" or "waiting". I can manually install at target clients but they do not report back to ERAS. I have used a Domain-Admin capable account for the ERAS service (did not choose local "Administrator" account)

I have other non-SBS networks with no issues.

Thank you!