I don't know how this happened, been using Ubuntu for a few years now (but I still consider myself a newbie):
Using 10.10. In the "places" drop down menu, when I click on locations such as Home, Documents, Downloads, etc, the Totem Movie Players runs, and tries to "open" the files in the respective folders --- instead of a Nautilus file manager window opening up.
How could this have happened? I looked in both Nautilus and Movie Player "Preferences", but was unable to find any customizable options that could be related.