Access 2007 ribbon. How to use the OnGetImage

[ARC]

Hello, I'm struggling with trying to get a ribbon toggle button to have one
image displayed if pushed in, and a different image if not pressed in.
Here's the entry for the button in the USysRibbons table:

<toggleButton id="cmdViewInactive" getImage="onGetImage" label="Hide
In-Active Parts" size="large" getPressed="onGetPressed"
onAction="RibbonVisible"/>

And here's my OnGetImage
-----------------------------

Public Function OnGetImage(control As IRibbonControl, index As Integer,
ByRef image)
Select Case control.ID
Case "cmdViewInactive"
'If pressed = True Then
' image = "RecurrenceEdit"
'Else
image = "FileStartWorkflow"
'End If
MsgBox "on get image"
Set MyRibbon = Ribbon
MyRibbon.InvalidateControl ("cmdViewInactive") ' '
Invalidates the cache of a single control
MyRibbon.Refresh

End Select
End Function
-----------------------------

Not sure what I'm doing wrong, but I can't even get the "OnGetImage" to
fire...

Many Thanks!