I have pretty much the same system
Other than the fact that my processor is AMD, I have the same system and the Atheros 5700EG. I can connect, but I cannot automatically reconnect. Each time I turn on the machine or I logon, I must reconnect manually. What a pain. What is your driver version?
I suspect that there may be a driver problem and that it is worse in your case. Rarely, but it does happen, my first attempt at connection fails as you described, but repeated retries seems to be successful. I noticed that instead of left clicking and trying to connect, right clicking and going to the full network center for connection works almost flawlessly.