Messed animation transition

When loading my character and its three DSQ animations in ShowTool, each run fine. But when I activate Transition (with default options) and change to another animation, the bones are sprawled in wierd directions and the model freezes. The sprawling is different in the three animations - in one, a bone is even detached from the rest and positioned elsewhere. In another, all nodes disappears (perhaps just out of sight? Can't find them).

If I double-click the animation, it skips the transition part and jumps directly to playing the animation - correctly. So if I don't use transition, everything works - but we really need it.

Do you have any idea what in the mesh or animation that causes this?