Databound Textboxes Not Accepting Values On TabControl

Question

I've got a tabcontrol with a number of databound textboxes on a tabpage
(Form1). I've got a button that the user clicks that opens a dialog (Form2)
and does a lookup from a database. The user makes a selection and chooses a
button wired dialog.ok to close the dialog (form2) and populate the fields on
tabcontrol (Form1). It all works except the textboxes don't retain the new
data when I tab across to another tab page.

Code To Open Dialog (Form1)=========================

private void btnLmoLookup_Click(object sender, System.EventArgs e)
{
Form2 LmoLookup = new Form2();
LmoLookup.StartPosition = FormStartPosition.CenterParent;
if( LmoLookup.ShowDialog() == DialogResult.OK )
{
txtBoxDocName.Text = LmoLookup.docFullName;
}
LmoLookup.Dispose();
}

Code To Create Public Variable (Form2)======================

public string docFullName
{
get{return
this.dsExtPhysLookup1.Tables["tblExternalPhysicians"].Rows[this.listBox1.SelectedIndex]["docFullName"].ToString();}
}