Vertical synchronization is meaningful only in fullscreen mode. This is your problem.
I have included to files which are the output of the framerate calc. the first is windowed the second is fullscreen. Notice the windowed one keeps going back to 60fps.
Nuh-uh. VSync can be overriden through the graphic driver's control panel, so you cannot rely on it being active even if you explicitly ask for it. And as you can see, it cannot be used in windowed mode. If you want to ensure the game runs at the same perceived speed regardless of framerate you need to use other methods, usually taking into account the elapsed time between two frames (there was this article that might come in handy though it's more about physics).
Dont I want to keep V-Sync on though? Can anyone have a look at the movement code because I want to make sure that an object moves the same amount on a 100hz computer just as a 60hz one. Maybe I can just rely on this (seems like) 'automatic' feature...!