the thumbnailer are registered under desktop, gnome, thumbnailers in gconf-editor, totem doesn't claim the video@x-ogg mimetype that's why those ogv are not thumbnailed, that's an upstream change request
the thumbnailer are registered under desktop, gnome, thumbnailers in gconf-editor, totem doesn't claim the video@x-ogg mimetype that's why those ogv are not thumbnailed, that's an upstream change request