Perusing the archive gives some hints, but nothing decisive:
On Getting rid of the jump when control moves up - sample code:
On Send Complete then MsgBox:just me wrote:Don't mix
GuiControl...commands for controls of your own GUI's if possible. [...] The coordinates used/retrieved by
GuiControl...commands are always relative to the GUI's client area, whereas
ControlGetPosretrieves coordinates relative to the window rectangle:ControlGetPos wrote:These coordinates are relative to the target window's upper-left corner ...