To further add to this thread, the IPhone does appear to have connection issues when using the office Wi-Fi and attempting to sync with Exchange. They apparently are not as often as with the Droid X, and sometimes the IPhone will synchronize, but connection issues do occur. Again, when the IPhone is switched over to the 3G network, the synchronization happens without issue.

And to add to our network information, the two wireless routers are not connected to the Exchange Server or any other network device. They are connected directly from the patch panel to ports on the the firewall so I do not believe any filtering device is blocking the synchronization.