SharePoint data connections have changed with 2010 - The expressions for the Validate field rule conditions will have changed:
For Valid Pin
../my:UserInfo/my:PIN = xdXDocument:GetDOM("PIN List_ElectronicSignature")/dfs:myFields/dfs:dataFields/d:SharePointListItem_RW/d:PIN[../d:Title = current()/../my:UserInfo/my:UserName]
For ...