1 - Is the DHCP server in the same broadcast domain?
2 - Have you properly mapped the VLAN to the WLAN?
3 - If you have more than one vlan, have you allowed those through the ge1 port?
4 - Is the AP set as a DHCP client and if so, is it pulling an IP address?
5 - Can you ping the DHCP server from the AP itself?
6 - Are the same VLANs allowed through the switchport the AP is connected to.
Assign a static IP address on the wireless client, connect to your wlan and ping the DHCP server, is the ping successful?
In other words, start by checking the route starting from the wireless client all the way to the DHCP server and make sure all are properly mapped and allowed through all ports.
Christoph S.