Problem with dragging files onto finder icon in dock

Hi there,

When I drag a file onto the finder icon in the dock I used to get a pop up finder window where I was able to navigate to other maps to find the right destination for my file. In Mountain Lion this is no longer the case and when I drag a file onto the icon I get the shaded background image because I don't have a finder window open already (this wasn't necessary in previous versions). I was wondering if there are more people experiencing this problem and if someone knows how to fix it? Thanks in advance!

Kind regards