The laptop is a Dell E6500 with an intel 5100 AGN card which appears, according to what I find on the intel site, to be certified draft 2.0. I'll try updating the drivers and disabling everything but N and see if that helps. The network is at another site so I'll have to wait until I can get back over there to test it out.

When you connect to the ssid, what signal speed is windows zero (or other utility) showing. In order for 802.11N to work, you need to enable WMM on the ssid, make sure the MCD data rates are set and that the channels are bonded and set to 40mhz channel width.

All of the SSIDs show the WMM Policy as allowed. The RRM DCA channel width is set to 40Mhz under 'a' and the selected channels are: 36,40,44,48,52,56,60,64,100,104,108,112,116,132,136,140,149,153,157,161

802.11n is enabled on bother the a/n and b/g/n networks.

Have you tried to manually set the channel to see if that works for you. If you look under the wireless tab in the 802.11a/n and then choose an ap, do you see the channels bonded there. I know you have it set globally for RRM, but look at the ap and try to manually set it.

That was it! I was using WPA-TKIP for my authentication. I created a "test" WLAN with no authentication and N was available.

Thanks for you help.