I guess that would happen if you don't first test to see if the menu is already showing....
if you keep calling the PopUp(X,Y) each time a mouse click takes place it'll just move around.
I guess it's a trick to find out if the menu is already showing ?
I guess on could try this, not sure if it will work.
if Not isWindowVisible(MyPopUpMenu.handle) Then PopUp(X,Y).
Normally most use the right click to do this..
Or just set a flag in the OnPopUp to indicate it's already opened and clear it in the OnClose event..