The Media Server nodes show all columns minimized. After widening them they return minimized on refresh. This same happens in the Now Playing with the Art & Details view.
I just upgraded from MM3 to 1357 on Windows 7 and have the same issue. If I'm browsing under My Computer and have the View set to Details, Column Browser, or Ar Viewer with Details, it happens to me. It's beyond annoying as I don't have a lot of my music in the library.