Fonts don't work!

[Stardust]

I begun working on a simple text editor around an extended richtextbox control, trying to improve the existing example from this page: http://www.codeproject.com/KB/vb/Wor...ick&fr=1#xx0xx, when i realised that the FontDialog doesn't work properly. Most of the fonts don't work. It just slips back into the default textbox font defined in the properties, or to the previous font. This is the code that opens the FontDialog box:

 Private Sub SelectFontToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles SelectFontToolStripMenuItem.Click

        If Not rtbDoc.SelectionFont Is Nothing Then
            FontDialog1.Font = rtbDoc.SelectionFont
        Else
            FontDialog1.Font = Nothing
        End If

        FontDialog1.ShowApply = True

        If FontDialog1.ShowDialog() = Windows.Forms.DialogResult.OK Then
            rtbDoc.SelectionFont = FontDialog1.Font
        End If

    End Sub

Font Broadway for example doesn't work, arial works, arial black works, batang works, bell mt doesn't work. I don't see the pattern.