firefox oddities when set as default browser

a few days ago i changed to firefox as the default htm/html application. I figured that i use it most of the time, actually firefox "told" me a few times that "it was" the default browser, but every time i had clicked on a kmail link up came konqueror! That was *before* i changed the default htm / html app thru control center. Now firefox comes up when a link is clicked in kmail, BUT, it often picks up some garbage from /var/tmp/kdecache with a new unrelated number to a numbered scene! This was tried at least 10x. Most links failed initially. When the link was copied from kmail and pasted to firefox, everything worked great. I think firefox just looks in the wrong place for the html, any easy way of changing that? thanks!