Wireless Network and IPad

I have been having an ongoing issue with my WiFi iPad 2 (as well as my iPhone 4). My WiFi constantly drops. Basically any time I want to use either of these devices I have to restart my router. My PC laptop works fine on the wireless. The iPad and iPhone both pick up an IP if I renew the lease, but then after a few seconds they drops it. I am not using any static IP configurations for any of the wireless devices in my apartment. Has anyone encountered this issue or have any recommendations?

My router is a D-Link, DIR-615 and I have updated the firmware.