Hey Greg
First thing: make sure your test kit is still good.
I used this
http://www.reeftime.com/reef-chemistry-calculator.asp to get the correct amount. His Mag is close to magnesium chloride hexahydrate i believe in the picklist
Do you have mangroves in your tank by any chance?
Also I am not sure Mg = 14000 will be safe. That is way too high and you need 132 cups to get there :-)