Program that should open in silent mode opens in full screen

I have a program with the following startup shortcut:

"C:\Program Files (x86)\MYOB\PDF Manager\PDFManager.exe" -s "C:\Program Files (x86)\MYOB\PDF Manager"

According to the software developer (MYOB Accounting) this shortcut should start the program 'hidden' and in the notifications area of the taskbar.  However, for every employee who logs in, this program actually opens full screen.  MYOB have (rightly or wrongly) suggested the problem is our system because no one else is reporting the problem to them. 

So, if anyone has any guidance on what is going on, or on how I can further troubleshoot the issue, I would be most appreciative.

Thanks,

Shane

Shane