I have three equally sized monitors (1280x1024 for that matter). The yEd main window is on the left monitor (primary), and there are two detached graphs on the 2nd (center) and 3rd (right) monitors.
If I drag a new node from the palette to the 2nd monitor, it works. But as soon as the cursor crosses the right-edge of the 2nd monitor, the dragged node pops back to the left edge of the 2nd monitor.
So the position of the dragged node matches the cursor's position on the third monitor, but the node is still on the second monitor, not the third.