[space-on-s]

I purchased Netgear WNDR4500 router and wanted to set it up the way that my MacBook Air (2010/Snow Leopard with latest updates) connects to it via 5Ghz network only.
The problem is that when I start up my Air one of the three times a message pops up on my MacBook saying "None of your prefered networks are available"
but below the message it offers to connect to the other found networks and my 5Ghz connection is listed there. If I press it connection starts immediately. Sometimes it connects without a problem.
If I add 2.4Ghz to known networks and MacBook can't connect to the 5Ghz (It's first prefered network in list)*it connects to 2.4Ghz. There are no such*problems with the other band.
However I'd like have automatic connection to 5Ghz allways not manual.
I tried different settings in router (security modes, no security, speed settings, network card access list, channels etc) but no luck...SSID's are CCC and CCC 5Ghz respectiveley.
Maybe there are some advanced settings in router to solve this or terminal commands in MacBook.

[medifastwoman]

I would try disabling the 2.4Ghz network to see if that improves things. You also might want to make sure the firmware on the router is up to date. It ether sounds like an issue with the airport drivers on your Mac or a bug in the router.