Specify terminal in launcher

[nullgraph]

Hi, I followed the this guide to add my own launcher to panel. I tested my .desktop file, the script opens in gnome-terminal and it works fine. But after added to panel, the script is opened in LXTerminal and does not work. (If you're curious, this is to start GAP). I don't know why it doesn't work in LXTerminal, as a work around, is there anyway to specify which terminal is used?

Here's my .desktop file

[Desktop Entry]
Version=1.0
Type=Application
Terminal=true
Icon[en_US]=gnome-panel-launcher
Name[en_US]=GAP 4.6
Exec=/usr/local/bin/gap4r6/bin/gap.sh
Name=GAP 4.6
Icon=gnome-panel-launcher
Categories=Development;
StartupNotify=true

And here's the part I added to the panel file

Button {
            id=/usr/share/applications/gap4r6.desktop
            terminal=1
        }

[humpty88]

Maybe..

Exec=gnome-terminal -e /usr/local/bin/gap4r6/bin/gap.sh