I do not know why it is crashing. But I know one way to find out (or at least try to): open up a terminal and type in "konqueror /mnt" and check all the output from Konqueror. There may be some nice error message there that you can post back to us. If not, try to go into /mnt with some other application. Also, what version of konqueror do you use? If it is very old, try upgrading since it may be some bug or something.
Just my thoughts on it.