Has this 505 been updated to v1.04?
After the FW was updated, was a factory reset done before configuring the 505?
What wireless modes are you using on the host router?
What make and model is the host router?
Try single mode G or N or mixed G and N?
Try setting a manual channel to a open or unused channel. 1, 6 or 11. 11 for single mode N if the channel is clear.
What security mode are you using? Preferred security is WPA-Personal. WPA2/AES Only. Some WiFi adapters don't support AES, so you might want to try TPIK only or Auto.
Any other WiFi routers in the area? Link> Use
InSSIDer to find out. How many?