There are many other things that can be affecting your connectivity. I would recommend checking the following:
- Make sure the Security encryption is set as WPA2-AES or WPA2-TKIP.
- Update the router’s firmware to latest. Here you have some more information:
http://www.intel.com/support/wireless/wlan/sb/CS-006321.htm
- As it has been mentioned earlier on this thread, disable the U-APSD:
http://www.intel.com/support/wireless/wlan/sb/CS-034875.htm
- Verify there are no other devices connected at 2.4GHz to the Wireless LAN when connecting for testing purpose.
Kevin M