There's a whole family of bugs of this kind with wobbly windows. One way of thinking about this is that the amount of wobbly-ness should be related to the amount of energy put into mouse movement - when the mouse stops moving for a while, the wobbly effects need to be damped out. There are numerous positions where a window can be slowly moved near other objects and a large amount of wobbling can persist indefinitely. One example is where a tall window is slowly moved so that the long edge is near a smaller window (about 1/3 the height of the tall window) - it appears that the two corners of the small window attract the tall window edge in such a way that the tall window's edge vibrates wildly.
In a similar way, the attraction to other windows should diminish with time, so that a small adjustment of a window is possible.
There's a whole family of bugs of this kind with wobbly windows. One way of thinking about this is that the amount of wobbly-ness should be related to the amount of energy put into mouse movement - when the mouse stops moving for a while, the wobbly effects need to be damped out. There are numerous positions where a window can be slowly moved near other objects and a large amount of wobbling can persist indefinitely. One example is where a tall window is slowly moved so that the long edge is near a smaller window (about 1/3 the height of the tall window) - it appears that the two corners of the small window attract the tall window edge in such a way that the tall window's edge vibrates wildly.
In a similar way, the attraction to other windows should diminish with time, so that a small adjustment of a window is possible.