Quick Launch toolbar won't show popup window

My Vista Quick Launch Toolbar just stopped working the way it shuld.
Several of my icons are showing in the toolbar, but when I click on the
'double arrows' the background turns dark. and it will NOT show the rest of
my Quick launch Icons.
The only way it will open the window with the rest of the icons in it is if
I have expanded the Quick Launch Toolbar to show the maximum of 9 icons on
the toolbar. Then if I click on the 'double arrow' it will display the rest
of the Quick launch Icons.
This is NOT how it has been working. Can anyone tell me how to get it to
display the popup window with only 2 or 3 icons showing in the toolbar?