I have built in wireless (with a switch & light on hardware for it) it's a Sony Vaio E-series with Ubuntu running alongside windows 7.
The button in the menu for
enable wireless is greyed out, and in the "edit connections" window when I click the button to make it
'On' it turns it
'Off' immediately while the wireless button is switched on & the hardware wireless light flashes once for 3 seconds.
Wifi works perfectly and the light stays on (solid) when using Windows 7, and it works fine with wired connection on Ubuntu.