I don't know if kwifimanager is a KDE app, I don't think so because it is in the networking section of Synaptic, not KDE, (if my memory serves me correctly). I don't have Gnome and have it installed, so not sure what's the scoop, nor do I use passwords as I only link to public networks so far. Check what buddy in the last post of this Ubuntu forum thread did to have an auto link to his wireless connection:
http://ubuntuforums.org/showthread.php?t=193930