Windows 7: Cannot connect to mixed 802.11A/N network

Here's our setup: we have a dual-band router, broadcasting two SSIDs (which are effectively the same network). The 2.4GHz band is using 802.11g only, and the 5GHz band is a mixed 802.11A and N.

My laptop is 'AGN' compatible and connected using 802.11N. The Xbox is connected to the same SSID using 802.11A. However, the problem lies with 2 of the other laptops. Both have 'ABG' network cards, and both can connect to the 802.11G 2.4GHz network without issues, but neither of these laptops will connect to the 5GHz network using 802.11A.

If I change the network settings so that the 5GHz band is A-only, the two laptops in question above connect fine. I can't see what's wrong - both cards are set to a/b/g mode, they all support WPA2...

Is there some sort of bug/feature that prevents connecting to a mixed A/N network?

Note: one laptop is Win 7 Pro, the other is Vista HP.

I am assuming you are using two different SSID's from the router if so:

on the two laptops go to the wireless adapter properties and click configure then go to the advanced tab and look for the SSID field it will most likely be blank and set to not present change that to the SSID of the A band network that should solve your issue.

I'm pretty sure those are fine... Both the SSIDs are hidden networks, so I have to manually connect anyway, and type in the SSID and password etc.

That is weird then why not just set it to A band since all the adapters seem to function ok on A

What kind of laptop is it? does it have the Intel 5100 wireless there has been alot of issues with that chip

Because I'm on N

I think they're both Intel PRO/Wireless ABG3945 cards.