I have a Dell Latitude E6510 with a DW1520 Wireless-N WLAN half-mini card.  I used to have a D-Link router which broke down so I purchased a new router which is a Linksys E2500.  I changed the configuration on my laptop to use WPA instead of WEP.  My router is configured with fixed channels (not auto).  My internet connection is continuously being dropped and I have to re-logon to everything (very annoying with vpn tunnels).  All my other desktops/laptops in the house work without problems.