konqueror won't start after iceweasel and/or icedove
 

I'm on debian stable (I guess), in a vaio.
konqueror consistently won't start if called after iceweasel and/or icedove and/or after closing/opening it a couple of times.
usually I have to restart X (ctrl-alt-backspace).
the process table shows it running but it does not open a window.
I don't know how to grab an error message; none appears if konqueror is invoked from konsole.

for general error messages try to open the file /var/log/messages with a text editor.

what's wrong with firefox?