running the file manager from a menu will always start an appvm if its not running. but it wont always run the file manager. running terminal, or any other apps always works. running nautilus from terminal always works too. just not the file manager. but, sometimes, the file manager will work from the menu.
I have noticed the same behavior on 3.2.
been a common problem for a while now on 3.2 as well. have to click file manager again to get it to open.