If you want to display information in a non-concert key, the item is Prefs-Display-Transpose.

The separate Transpose dialog is to transpose the thru part on your connected MIDI keyboard, or transpose songs when loaded to a different key, which is not related to non-concert instruments). The 'transpose by' on that dialog causes a thru part played on your keyboard to be transposed to a different key - see the fly-by hint for more details on that.

As mentioned, you can also do this from the notation window (options-transpose), and also from the Practice window.

Have Fun!
Peter Gannon
PG Music Inc.