I was using several Unix programs through Mac OS X’s X11, and I was experiencing several crashes (emacs when trying to resize sub-windows, nedit when trying copy/paste, even matlab was spewing error messages) with an error of the type
X Error of Failed Request : BadAtom
After fiddling a while, it appears this is due to a modification of ssh which does not accept trusted X11 cookies anymore. I added
in the local .ssh/config, and crahes begone ! Joy.