Move Not Working - Blender 2.55 2.57 Mac OS X

Works fine in 2.49b however, the later down loads move doesn’t work.
I go into user preferences and turn rotate off and move on with the same button controls and nothing happens. Reset the same buttons to Rotate and rotate works.
Yes I have tried emulate 3-button mouse - makes no difference. Simply uncheck rotate and rotate stops. Turn on move to mouse middle and nothing. turn back on rotate at mouse middle and rotate works.