If you disable the filemanager module you can't have files and shortcuts on your desktop.
To use a custom filemanager and have working desktop icons enable the filemanger module, open the places gadget settings, select 'use custom filemanager' and fill in the command of the filemanager you want to use. Also make sure 'show in menu' is selected in the places gadget settings because Texstar patched the e filemanager out of the menu to have the desktop icons working.