After upgrading from 12.10 to 13.04, whenever I attempt to open a file from any application (firefox, thunderbird, vlc, etc..) besides gedit, the file browsing window doesn't display any files and is unresponsive. I end up having to xkill the application. The nautilus file manager appears to be working fine (i.e., it allows me to browse through directories, etc...) when I start it from a terminal window. It might be an easy to fix problem but I haven't found any reference to someone else experiencing it. Can someone please help? Thanks.