custom widget with gesture handlers

I created a custom widget (with TouchKit) extending Composite and using a Canvas for initWidget() for custom drawings.
All is working fine, but i'm wondering that gesture handlers on the canvas not working. None of the gesture events onGestureStart, onGestureChange or onGestureEnd will be called.
Touch handlers only returns a single Touch.

Is this a limitation of TouchKit or is there a trick to receive multi touch events?

thx,
Chris

now i get multiple touches working.
I put my Canvas in a VerticalPanel and use the VerticalPanel for initWidget() of the Composite.
But still gestures are not recognized.
I can calculate the scale of a multi touch gesture now from the Touches in onTouchMove, but gesture events would be more comfortable.
Anybody nows how to receive the gesture events?