I haven't picked up on a pattern yet, but ~50% of the time the window shifts half the height of the title bar when I save a document. If it matters, I don't use my mouse to click save, I always use CTRL+S. I don't think it's happened when using Save As. It doesn't matter if the window is free-floating or docked to the side of the screen or maximized, it still happens. Typically, the window shifts up on the first save and down on the second save.
I've searched and searched and can't seem to find anyone else with this problem. Does anyone have ideas on what's going on?