User-Agent:       Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.13) Gecko/20060418 Fedora/1.0.8-1.1.fc4 Firefox/1.0.8
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.13) Gecko/20060418 Fedora/1.0.8-1.1.fc4 Firefox/1.0.8

Xfce 4.3.90.1
Using menu editor on fresh account: no ~/.config directory before Xfce install. I changed some entries and saved. It was trying to save into system directory but probably failed because of permissions. Menu editor was not reporting a error message nor was it saving into proper place under .config directory.

Reproducible: Didn't try