Time Capsule + Intel 4965agn adapter = 5GHz 802.11n problems

I'm running a Dell XPS M1330 that is equipped with an Intel 4965agn wireless adapter, which has no problem connecting to my wireless-n Netgear router at 5GHz. I upgraded to a TC for the wireless capabilities plus the NAS. However my network adapter doesn't see the TC's 5GHz 802.11n signal, only the 2.4GHz 802.11n (144 Mb/s MAX) or the g/b. Intel claims it is a compatibility issue and I should go back to the Netgear, but I love the TC's stability and capabilities so I would rather find an adapter that is compatible with the TC.

Was the Intel guy right, and there is a compatibility issue (which doesn't make sense)?

Does anyone know of an adapter that will work at 5GHz and give me the potential 300 Mb/s?