Mike, unsure why your way isn't working but there's a simpler way
RichTextBox richTextBox = GetTemplateChildFromDictionary("richTextBox") as RichTextBox;
if (richTextBox != null)
{
richTextBox.PreviewMouseDown += new MouseButtonEventHandler(this.richTextBox_MouseDown);
}
Keyoti.RapidSpell.Wpf.RapidSpellAsYouType rapid = new Keyoti.RapidSpell.Wpf.RapidSpellAsYouType();
rapid.TextBox = richTextBox;
Unless you wanted to do it your way?
Dan
Dan Wright