For some reason, the first press of Command in the VM is not recognised. This is especially noticeable when selecting files in a list : hold Cmd, select an item, then a second item: the first item is deselected. However, re-selecting it and subsequent items, and normal behaviour occurs, i.e. all selected items remain highlighted. This would be a minor(ish) inconvenience except for one thing : I cannot boot the VM into Single User mode as the Cmd key press (Cmd+S) is not recognised. Why is this happening and what is the solution?