Looks like the kompozer package doesn't contain the needed .desktop file.
To manually create one: as root, in a terminal enter:
mcedit /usr/share/applications/kompozer.desktop
Next, copy the following information:
[Desktop Entry]
Name=KompoZer
Comment=WYSIWYG Web Editor
Exec=kompozer
Icon=/usr/lib/kompozer/icons/mozicon50.xpm
Terminal=false
Type=Application
Categories=Application;Development;
Encoding=UTF-8
Paste it into mcedit with key combination Shift-Insert
Press F2 to save, F10 to exit.
Now run the menu updater and you should get a Development sub-menu with Kompozer in it.