FreeTextBox

I pulled this from another thread, this worked for me. Basically the same as you but it assigns the clientID on the TextChanged:

protected void FreeTextBox1_TextChanged(object sender, EventArgs e)
{
         FreeTextBox1.Text = Request.Form[FreeTextBox1.ClientID];
}

yep, that's how I do it now also.  To bad it wasn't answered in this thread before. 

The problem must be internal in the control.  I hope the author still fixes it because I think the style of the 4.0 control is more modern then the one before.