The .desktop file for nmapfe is broken: (1) There is a typo "exec" must read "Exec" (2) The proper location for it is /etc/X11/applnk/Utilities and not /usr/share/gnomes/apps/Utilities In particular, if you choose to install KDE only this will be the only item in the Gome menue, which makes no sense.
This will be fixed in beta 2. Tim