I have had this issue for a while. I am from the USA and do not offer free international shipping. I only offer free UPS Ground in the United states if order is over 49.99. Customers who order from Canada are only offered USPS 0.00. I am not sure what is going on here, I have changed nothing. Here are my shopping cart price rules.
If ALL of these conditions are TRUE :
Subtotal equals or greater than 49.00
Shipping Country is United States
Shipping State/Province is not Alaska
Shipping State/Province is not Hawaii
Shipping State/Province is not Virgin Islands
Shipping State/Province is not Palau
Shipping State/Province is not Guam
If ANY of these conditions are TRUE :
If ALL of these conditions are TRUE :
Shipping Postcode greater than 00900
Shipping Postcode less than 96200
If ALL of these conditions are TRUE :
Shipping Postcode greater than 97000
Shipping Postcode less than 99500
Shipping Country is not Canada
Shipping State/Province is not Ontario
Shipping State/Province is not British Columbia
Shipping State/Province is not Alberta
Shipping State/Province is not Manitoba
Shipping State/Province is not New Brunswick
Shipping State/Province is not Newfoundland and Labrador
Shipping State/Province is not Yukon Territory
Shipping State/Province is not Saskatchewan
Shipping State/Province is not Quebec
Shipping State/Province is not Prince Edward Island
Shipping State/Province is not Nunavut
Shipping State/Province is not Nova Scotia
Shipping State/Province is not Northwest Territories
Shipping State/Province is not ...
Shipping Country is ...