I've got that problem since Daum Dosbox 0.70 2007-07-29.
I have a Logitech Rumblepad 2. When starting Dosbox as a Window everything is fine. But when I switch to fullscreen and press a button on the pad, the Dosbox crashes.(By the way: starting in fullscreen mode isn't possible anymore. There is an error: Could not set fullscreen video Mode 1024x768x32 DirectDraw2, Set CooperativeLevel: InvalidParameters.)