Hi, I've seen this problem a lot here but none of the solutions were good for me, I'm afraid :(
Running 3.5.1, my index-page admin bar is not there and the switches between HTML/editor when making a new post don't work. There might be more issues but so far, I've come across these two.
Curiously, the adding of define('SCRIPT_DEBUG', true);, one of the many suggested solutions, f***ed-up the dashboard even more, with almost everything breaking down.
I'll be super-grateful for any advice upon this problem, becoming quite desperate here :(