If I try recording a macro for what I think you are trying to do (but from your description it is not 100% clear to me what this is), I get the following, and it always works for me:
<Macro name="xxx" Ctrl="no" Alt="no" Shift="no" Key="0"> <Action type="3" message="1700" wParam="0" lParam="0" sParam="" /> <Action type="3" message="1601" wParam="0" lParam="0" sParam=" " /> <Action type="3" message="1625" wParam="0" lParam="0" sParam="" /> <Action type="3" message="1602" wParam="0" lParam="0" sParam="&nbsp;" /> <Action type="3" message="1702" wParam="0" lParam="512" sParam="" /> <Action type="3" message="1701" wParam="0" lParam="1609" sParam="" /> </Macro>