Cannot browse folder from save's window dialog

Hi suddenly I cannot change the directory where save open document (I've tryied with preview and text edit), more precisely when I try to choose another folder whatever, but different from the default, I don't see its content but only an icon of the folder and a determining size text, and save button greyed.

(Par. I can see only shared folder from the side bar of finder's windows.)

Could be that I've opened an ftp server with Finder and it was displayed with many folder with same name "_?" ... and that cause some problem?