How do I configure a SecureNAT client connecting to a ForeFront TMG 2010 Array (managed by an EMS server)?

Hello,

I have set up the following mini virtual network of servers:

Name:  ARRAY1
Role:  TMG Array member #1
NIC 1: 10.1.128.1/255.255.0.0 DNS: 10.1.128.3
NIC 2: External Public IP for Internet #1

Name:  ARRAY2
Role:  TMG Array member #2
NIC 1: 10.1.128.2/255.255.0.0 DNS: 10.1.128.3
NIC 2: External Public IP for Internet #2

Name:  DC
Role:  ADDS server, DNS server
NIC 1:  10.1.128.3/255.255.0.0 Default Gateway: 10.1.128.1 DNS: 10.1.128.3 (self)

Name:  EMS
Role:  EMS Server
NIC 1:  10.1.128.4/255.255.0.0 Default Gateway: NONE. DNS: 10.1.128.3 (self)
DNS Entry for the actual array called "TMGArray" points to 10.1.128.4.

Name:  VM1
Role:  Windows 7 Client
NIC 1: 10.1.128.5/255.255.0.0 Default Gateway: 10.1.128.4 DNS: 10.1.128.3

Independent internet connectivity on the two ARRAY* servers was verified and both ARRAY* servers were successfully added to an array called "TMGArray".

Now, the problem I am having is configuring clients to connect to the TMGArray for internet access, instead of directly to an individual TMG Server (which still works, btw).

In other words, for VM1:

NIC1: 10.1.128.5/255.255.0.0 DG: 10.1.128.1 DNS 10.1.128.3 <-- WORKS

but

NIC1: 10.1.128.5/255.255.0.0 DG: 10.1.128.4 DNS: 10.1.128.3 <-- DOES NOT WORK

How should I be configuring my client so that it connects to the internet via the TMG Array (EMS) and in SecureNAT mode (i.e. no browser config required)?

All help is greatly appreciated!

Thanks,
Waqqas