i'm writing here just to not create a new post.
I have a similar problem using Ubuntu 13.04: the wireless connection seems to be activated but when I try to surf on the Internet, Firefox doesn't find Google.com. So I tired to ping www.google.com from the terminal but it gave no answer. Then I turned everything off and restarted everything: the ping this time worked but when I tried to open the browser, it failed again, as the browser did.
Thinking Ubuntu had some problems (I'm new on this OS), I download and installed Lubuntu, hoping something could change. Actually it didn't. Nothing different. Finally I checked what kind of driver was being used and, for Ubuntu and Lubuntu, it was the same: lw4965. The driver is not working properly? Should I change it?
Thank you for any help!