/silent not working with Single File Installer

I have created a Single File Installer and when I add the /silent switch it does not work.

Package I created is called FrontEnd (installs SAPGUI7.4, NWBC5.0, Business Explorer), command line name FrontEnd.

Command line:

C:\SAPInst\FrontEnd.exe /Silent /Package="FrontEnd"

Nothing happens.

When I run the EXE without the /silent it works fine.

When I run the EXE with /noDLG a box shows up, "Extracting files", then a quick SAP splash box, then "Removing temporary files".

Does anybody know of a solution for this issue?

Thanks.