StickypopUpMenu Flickers at first popup

Hello
 
With ShowMenu(Mouse.Cursorpos.x,Mouse.CursorPos.y) menu flickers a short time before final popup.It appears for some milliseconds at coord 0,0 of the screen. How can I solve this problem?
 
Regards Sascha
 
I Use Delphi 2006 and v1.3.1.3