I'm writing this one in english because it may be helpful to some people. I am quite pissed off with the number of stupid bugs that are plaguing Apple's latest X11.app . Especially the fact that the so-called "emulate three button mouse" option is completely broken. In Tiger, it used to map 'option+click' to middle click, and 'command+click' to right click. In Leopard it is: 'option+click' = right click, and 'command+click' = 'Meta Middle-click' ... WTF ?!

issuing these commands in a terminal:

defaults write org.x.X11 fake_button2 option
defaults write org.x.X11 fake_button3 control

restores the old behaviour for middle-click, and uses control for right click (so you get a real right click, and a meta-right-click). If anyone knows how to get right-click with 'command+click' I would be interested.