There could be a number of reasons.
1) The number of baths is listed incorrectly on your property card at North Castle
2) The number of baths is not populating into Zillow/Trulia's system from their tax service
3) Zillow/Trulia data made an error
If your house is for sale then it is your agent's responsibility to make sure the information remains updated as this is a third party site and information is not always transferred properly from the MLS.
Licensed Real Estate Salesperson in NY and CT
Julia B. Fee Sotheby's International Realty