Problem running console applications from .desktop

[Bela Markus]

I have a problem running console applications from a menu. Take 
following example, fdisk.desktop:

------------------------------------------
[Desktop Entry]
Version=1.0
Encoding=UTF-8
Type=Application
Name=fdisk
Comment=fdisk test
Categories=Application;
Exec=sudo fdisk /dev/hda
Icon=dialog-warning
Terminal=true
StartupNotify=false
------------------------------------------

Placing it to ~/Desktop works as expected. When same fdisk.desktop 
placed to /usr/local/share/applications it appears in the menu, but when 
executed behaves differently. Terminal window opened and closed 
immediately, so can't see mwessages if there was any. When fails, no 
syslog record added.

Same happenes without sudo and other apps, so it is not sudo or fdisk 
related.

It is Xfce 4.6.1 on Tiny Core Linux 2.10 ported by me. When 
Terminal=false it works as expected.

Any idea?

Thanks... Béla