Package: 9menu dpkg operations (eg. `dpkg --purge 9menu`) failed for me with the message "exec format error" on Debian Woody. Looking at the problem, it seems that 9menu.postinst and 9menu.preinst in /var/lib/dpkg/info lack the line "#!/bin/sh" at the top - causing the error, as the files are then treated as a binary.
Hope this is useful, Grahame -- Grahame Bowland University Communications Services, The University of Western Australia Phone: +61 8 9380 1175