Same issue Dell Inspiron 15z with 2230 card and Windows 8. I have iPads and laptop tops which can connect fine to the wireless router from two floors away. This machine is on top of the wireless and the signal is strong but it is unable to ping the router.
I rolled the driver back to 15.5.6.48 from the 15.8.x driver and its much better. Time will tell if it fixes it.
Mick