Without doing your research for you on google, you will probably be looking at either modprobing the ath5k module and rerunning yast2's network configuration wizard, or using the older madwifi. As a last resort try ndiswrapper.
I did find this openSuSE forum article:
PS. I don't know where I got it in my head that you are using openSUSE after (mis)reading the posts. Could you put your distro in your user profile. That will help people familiar with your distro give you the easiest advice. What I said about YaST2 is SuSE specific.
There may have been a problem with the AR242s firmware requiring the latest updates or kernel version (post march 2009) to properly detect the device, from the gist of what I read while searching info on this device.