cannot connect wireless w/windows 8

I have been unable to connect two windows 8 laptops (dell and asus) to my home network (and internet). At the same time I have connected 2 xp laptops and 3 kindles with no problems. My security consists of using mac addresses only and all other security is turned off.

The offending laptops will also only show the 5gz and not the 2.4gz in available networks (one laptop is brand new and the other is about 1.5 years old). I have also disabled all security on one of the laptops to see if that was the problem (it was not). When trying to connect I have two basic reactions. The first is that its taking too long (cannot connect) and the other is that there is limited connectivity. In addition to that I am sometimes told that the ip address is not right (malformed, I think).

I got the mac addresses, of the offending laptops, by the standard cmd/ipconfig /all path and choose the wireless wi ip but have also tried the other wireless as well with no better results (just making sure)

I also have an edimax extender plugged in and it works. The laptops also show fewer network connections than my asus 1000ha w/d-link dongle. My own laptop, incidentally, is clicked into the 5gz network connection directly from the router (edimax kinda redundant <g&gt

I posted this in windows 8 topics as I think this is probably a windows 8 problem given the ability to connect other machines with no problem.

The router is a netgear wndr3400 and is working just fine for all but the windows 8 machine.

Thank you..........