I have had this problem too. The only solution is to go to their name under Vendors (vendors and contractors are one and the same) and add it as an attachment to the Vendor Details. That way you have it attached to their profile if you need to access it. If you use Quickbooks as your payroll solution, they will use the info you have entered (all you need is the name, tax ID and address and they will send out the w9s electronically.