Problem with Power Manager Autostart in MATE

[scaramanga9]

I have been experimenting with LM12 MATE in my virtual box. I am having a problem with the power manager. I installed xfce power manager and added it to the list of Autostart programs using the Autostart preferences tool. However, when I login in xfce power manager does not start and I have to launch it using terminal. Does anyone have any suggestions for how to fix this problem so that xfce power manager automatically starts when I log in? Thank you.