Info Window can't be moved

Depending on where the Info Panel is docked, it does lose the little tab. But if you grab it just at the tippy top in the upper left-hand corner, you can click and drag it to another panel. Depending on where you dock it, like say you dock it with the Effects tab or something like that, you'll see the Info tab pop back up.  And if you want to close it, you can just hit Ctrl or Cmd+W, and that will close it when it's selected.