Error - field does not exist in the current context

Hello:
I am getting a very strange error.  i have declared a field send_outlook_appt.  Even though intellisync is picking up the field name, I am getting an error saying that it does not exist in current context.  My program runs as expected in dev.  When I try to build/publish my website, that's when I get the error.  Here is a snippet from my code.
public class arcTraining { private string connstring = ConfigurationManager.ConnectionStrings["xxxx"].ToString(); protected int _training_id; public int training_id { get { return _training_id; } set { _training_id = value; } } protected int _web_site_page_id; public int web_site_page_id { get { return _web_site_page_id; } set { _web_site_page_id = value; } } private string _outlook_appt_subject; public string outlook_appt_subject { g ...