When using a transparent stage (StageStyle.TRANSPARENT), MOUSE_MOVE events are not fired when the mouse is over any part of the stage that is visually transparent. This occurs even if the cursor is within a Node's bounds, so long as the pixels under the cursor are transparent.

I have attached a simple example that demonstrates what I mean. Move the mouse within the box and no events are fired. Move the mouse along the narrow border and events are fired. Comment-out the 'stage.initStyle' line or add '-fx-background-color: white;' to the root's style, and events are fired when you move the mouse within the box.