sudo apt-get install linux-backports-modules-intrepid
Add ath5k on /etc/modules, reboot.
Then you need to switch the drivers on System->Administration->Hardware Drivers. Deactive the current default driver (Atheros 802.11 wireless LAN cards) and activate the 5xxx series of Atheros 802.11 wireless LAN cards.
I also encountered a new problem in Skype. It seems my Logitech S 5500 mic is very choppy, the mic is connected via USB. I didn't have time to fix it, so I just activated the mic of the laptop which works with Intrepid. This is likely a software problem, as the S 5500 works fine with the HP 6910p on Intrepid.