MouseDown, MouseUp - wrong mouse position?

[bodeg]

I registered to the dsImageDisplay mouse events - MouseUp and MouseDown.

When I press the left mouse button without moving the cursor - I do receive those events but with different locations (MouseEventArgs).
I think the offeset is consistent, and changed when the control is resized.

When pressing the right mouse button - the locations are equal.

The dsImageDisplay is docked (try also none docked) inside a tableLayoutPanel.

Any idea?
Best regards, Bodeg.