Ok now it works fine, thanks Eric.
unfortunately i still have a problem when i try to create a marker,
then i set an icon to it (through MarkerOptions) and add a
MarkerClickHandler.
If i try to mapWidget.getInfoWindow().open(event.getSender(), new
InfoWindowContent("test")); i can't show info window, on the contrary
if i remove the icon it works good.
Where is the problem? thanks again