WDA Network Setup Problem

I have an Airport Extreme connected to a router through a switch. It works fine if the Wireless Mode is set to Create a wireless network. But I want to set it up to be the main device for a WDA Network. As soon as I switch it to Participate in a WDA network it disappears from Airport Utility and I can't access it any longer. However, the network connection is still active but the status light is green with an intermittent amber flash.

In addition, I have it set up in Bridge Mode so the primary router still assign IPs through DHCP.

I just set up a network at my bosses house using an Airport Time Capsule and its working beautifully but the big difference is that its connected to a DSL modem versus an office router.

Does anyone have any suggestions?