Kubuntu didn't work with my HP laptop. I switched....
I spent a lot of time trying to get my wireless card going on two of my laptops, using Kubuntu, but had no success. So I switched to PCLinuxOS. It has all the codecs and non-free applications to make your wireless card work. I'm writing this on one of those laptops right now. Ubuntu tries to be a pure Linux, and therefore, you have to work real hard to get your wireless running. The necessary applications to make it work are not easily attainable. Perhaps it's time to switch to a distro that's not afraid to include the non-free applications to make your life easier?
(K)ubuntu is a fine distribution for desktop machines, but kind of lousy for wireless usage. Save yourself some pain, try a different distro.