orange juice leaves white powder?!
that's really odd..call up flordia natural or write to them with the date production codes and let them know...not only will they probably send you a coupon for a new juice carton, but they may improve their formula and not let that happen again.
-It's VERY likely to be the Calcium...-As Dishwasher Soap is not Supposed to leave any Residue behind ( as it would show up- on the Glasses). :)