Comment 10 for bug 667071

I have found a workaround. Something messes up file associations for the 'folder' type. I can't find the reason, but here's how I have fixed it:

* Open the Computer from the Places menu
* open a partition, which does have some folders in it
* right click on any folder
* select Open with Other application from the context menu
* select the File browser as the app to open with
* make sure the "remember this application for 'folder' files" is checked
* click OK

This solved the problem for me, hope it helps you too :)