Just purchased a new XBOX 360 250GB.
Network tests work fine using a wired connection but wireless fails with the error "Can't obtain IP address from your router".
Have tried all the troubleshooting tips on the support page with no joy - the XBOX see's the wireless network but can't connect.
The router is a D-LINK DIR-615 Hardware Version C2 Firmware version 3.01 - the device tells me that there are no firmware updates available.
I couldn't find this device/firmware version in the XBOX compatibility list.