I'm using Ubuntu 12.10, on a TOSHIBA Satellite L755 laptop, and using a Cradlepoint MBR-1000 wireless router.
The wifi supposedly works fine on my sisters' and mom's laptops, and my dad uses a wired connection through the router. Nobody else has the problem.
It shows that I'm connected and everything. The network manager GUI shows that everything is going just dandy... but it's not. I'll be able to load a page or two, then I have to disconnect, and reconnect to the router to get it to work again for a couple minutes. I noticed when I was downstairs, close to the router, this problem seemed to go away (at least, I was connected for a couple of hours without running into this problem).
When I run
ping -n 126.96.36.199
it shows this while the connection is still running fine
64 bytes from 188.8.131.52: icmp_req=1187 ttl=47 time=665 ms