Try this from a post on the Ubuntu Forums:
Alt+F2 and in the window that opens, type Nautilus
When the file browser opens,right click on a folder and select Open with Other Application and then select File Browser then Open.
You should now be able to open folders in the Places menu.
Hope it works for you.
HP Pavilion 17 Notebook, 8GB DDR3, 2.5GHZ A10-APU, Radeon HD 8650G