my linux story: back to wifi problems

seemingly everything was okay. i set up a new connection, typed in wep key, and it worked. though soon, after installing kubuntu-desktop, which needs its own config for wifi (why?), it went wrong, didn't connect anymore, and the key was showing other data than typed in (i believe it's because of automatic converting between hex and ascii). to heighten the confusion, ubuntu doesn't list "hex key" in its possible key format list. i had to: delete the connection; set it up again; restart the system. WHY?