I have a macbook 2.0 core duo and I installed a retail version of leopard the other day. I installed over the existing Tiger setup(upgrade install not clean). Everything works just fine except when I click on ichat it looks like it wants to open but no setup window pops up. I do get the top of the screen menu. I never setup with 10.4 so maybe I am doing something wrong. Under tiger I would get a setup window that would pop up.