I have an existing network which works OK; it comprises a WZR2-G300N wired to a Netgear non-wireless ADSL router. The WZR2-G300N is a UK model with 1.52 firmware level. My son's brand new Windows 7 Dell laptop (XPS15R, I think) won't work with it (on wi-fi). It gets an IP address from the DHCP server (on the Netgear) OK, & Windows says it's connected, but also says "Unidentified NetworK", and cannot connect to the internet. The laptop originally had an Intel 1000N wifi card. Following several hours on the phone to Dell, they agreed to replace the wifi card - with a new Broadcom model. It still doesn't work - same problem as the Intel one. After that, the Dell engineer is convinced that the Buffalo AP is faulty, or too old spec to work with the latest wifi cards. The laptop works fine on wired Ethernet, and also works OK on wifi at at my son's work.
Other PCs in the house work fine on Wi-fi - 2 are XP desktops, one is a Vista desktop, and another is a Windows 7 laptop, but this one is at least 2 years old. From the new PC, I can ping the Buffalo box OK, and other wifi devices also, but I can't ping any wired devices.
Do I need to buy a new wireless AP, or can I do something to fix this problem?