Well, I have a HP Envy dv6t-7300 laptop that came with a Ralink RT5390 WiFi card. Everything was working perfectly, and eventually I press the WiFi button in my keyboard to toggle the card on/off. Until today, all worked right: if the wifi was off (wifi LED amber) and I press the wifi button, after a few seconds the LED turn white and everything works. If I repeat the process, the wifi LED turn amber and the card get disabled, but now, I can't turn it on anymore.

running sudo rfkill list all I get:

0: phy0: Wireless LAN
Soft blocked: no
Hard blocked: no

1: hp-wifi: Wireless LAN
Soft blocked: no
Hard blocked: yes

So, I ran sudo rfkill unblock all but nothing changed. As a side note, if I run sudo ifconfig wlan0 up, the indicator LED gets white (indicating that the card was enabled), but Ubuntu still say that the card is blocked by hardware.

Extra information: the card works without issues in windows and in Ubuntu installer (booting from a live CD). I'm using the card out-of-box, using the drivers already included in Ubuntu 12.10. The module rt2800pci is loaded and working fine, not blacklisted, etc, etc. The card and the button toggle worked flawlessly until today, when I toggled it off and can't turn it on anymore...

The problem is back, but in a different manner: if I don't press the wifi key a few times during the grub loading, in the login screen the wifi button will be ambar (disabled), pressing it will toggle it white (enabled) or ambar (disabled) again, but ubuntu still says that the network card was disabled by hardware and doesn't connect...

In other words, if I don't press the WiFi button a few times when Ubuntu is booting, it will be stuck with the "network card was disabled by hardware" message, even if the light is white (enabled). Any clue? Maybe a error in some startup script or config file?