Wireless Acccess Point DHCP Issue

Here is my scenario;
Windows 2003 AD (DHCP, DNS), 100 users
When I connect an AP, the client connects without an issue for 30-60 seconds. I’m able to Ping externally but all of a sudden, no connection.

If I’m wired to one of the ports of the access points, I have connection with no problem.

I have tried different access points, DD-WRT with AP settings, DHCP forward, etc.

Please anyone HELP!

Thanks again for the help/suggestions!