Starting in 7.0 and continuing through the latest 7.0.2 EAP, Idea refuses to open any jovadocs in an external browser for me, in any of my projects. I'm running under Mac OS X 10.4.10, not Leopard. I've tried both variants in the General preferences: "use system default browser" and the "open" command. When I hit shift-F1 (or use the menu), nothing happens. No error or anything, nothing reported in Console.app.
I kept my copy of Idea 6 around, and it works fine opening javadocs fine in Safari on the same projects. So nothing has obviously changed in my machine setup.