Excel 2010 :: Control ENTER And EXIT Event Firing With Frames Active?

I'm having some trouble getting control ENTER & EXIT events to fire properly when having controls embedded on frames within a userform. I'm using Excel 2003, 2007, & 2010. Here's the userforms I'm working with:

With FRAME:

Without FRAME:

In both cases, the DESCRIPTION field is disabled. The selectable controls on both are a combo-box, textbox, listbox, & 2 buttons. On the FRAMED version, the combo-box & textbox are contained on a FRAME.

Here's the code, same on both userforms:

Code:
Option Explicit
Private Sub cmbRecipes_Enter()
ListBox1.AddItem "ENTER - " & cmbRecipes.Value
End Sub
Private Sub cmbRecipes_Exit(ByVal Cancel As MSForms.ReturnBoolean)
ListBox1.AddItem "EXIT - " & cmbRecipes.Value
End Sub

All this is doing is posting a message to the listbox when the combo-box ENTER & EXIT events fire. This works as expected without the FRAME, ENTER is shown when the combo-box is entered and EXIT is shown as focus is moved to another control. But when running it on the FRAMED version all I get is a single ENTER event recorded regardless of how I move the focus through the control set.

Another oddity is that if I have more than 1 control that can receive focus on the FRAMED version, it appears to work correctly.