Validate Field Function on online customer forms corrupting the State list

We have online customer forms that include fields such as the Company Name, Email, Phone, Fax, State, Country fields, etc. When the Country is changed from United States to Canada, the State list used to update itself to Canadian provinces. However, since Friday morning, this hasn't been working and I can resolve the issue by removing a Validate Field function that's on the online form client script. All this function does is check if the Phone or Fax fields are not more than 21 characters long. I wonder why this script is breaking the State list update and why it