If you're talking about the left menu (with folders for Requirements and Resources, for instance), I don't have any problem opening and closing using Safari and Firefox. Are you seeing the problem with these browsers?
Just did a fresh install of Tiki 6.3 and linked to and upgraded my database from 5.3. I cleared the cache. The site looks fine except for one thing so far: I'm using the coalesce theme, and the little manila folders for the menus no longer toggle open and closed to reveal the files in a given folder. They are set at the open position and won't close. Am sure there's an easy way to fix this issue, but I don't know what it is — can someone fill me in on it? Much obliged in advance for any assistance.