I am not into konqueror these days, so no idea about that. As for firefox, most problems comes from corrupted profiles, silly extensions, etc. So, first I would try using a clean profile, the easiest way to do that is to create a new user to test with. If the problem goes away then you know that there's something wrong in your profile, try disabling every extension and plugin before doing anything else.
-- Jesús Guerrero
