When editing a command button on Windows XP, using a small 15" monitor (i just mention this, because it perhaps wouldn´t occur on a monitor with enough space), in the "arguments" list of the extended editor, some sub arguments on the right will appear in a disconnected manner (from the drop down cascade) at the far left, whereas i would expect them to appear directly attached to that menu at the left side.
So navigating to those sub arguments with the mouse doesn´t work, because the cascade will close once the mouse cursor is moved over the gap towards the sub args on the left. It´s still possible, though, using the up/down arrows to select them.