Two part bug:
Part 1) NLA Editor menu was calling wrong operator
Part 2) r35829 broke NLA scaling, since it only checked that the
transform mode used was allowed in the Action Editor (probably
confused by Part 1)
ui/ --> startup/bl_ui
op/ --> startup/bl_operators
scripts/startup/ is now the only auto-loading script dir which gives some speedup for blender loading too.
~/.blender/2.56/scripts/startup works for auto-loading scripts too.