Problem invalidating toggle button on ribbon

[PRMiller2]

Hi all,

I have the following code:

Public gobjRibbon As IRibbonUI

Sub OnRibbonLoad(ribbon As IRibbonUI)
    ' Callbackname in XML File "onLoad"

    Set gobjRibbon = ribbon
End Sub

Sub OnActionTglButton(control As IRibbonControl, pressed As Boolean)
'ToggleButton
                              
    ' Callbackname in XML File "onAction"
    
    Select Case control.id
        Case "tgbSnapReportPrint"
            ' tabSnap.grpSnapReports
            gobjRibbon.InvalidateControl ("tgbSnapReportsPreview")
        Case "tgbSnapReportPreview"
            ' tabSnap.grpSnapReports
            gobjRibbon.InvalidateControl ("tgbSnapReportsPrint")
    End Select

End Sub

The purpose of this code is to not allow both the tgbSnapReportsPrint and tgbSnapReportsPreview buttons to be in a state of "pressed" at the same time. If Print is pressed, then Preview should not be, and vice versa. The code does not fail on a debug/compile, and it does not error out during execution. However, the button that I wish to turn off remains in a pressed state unless I physically click on the button itself.

Any suggestions as to what I can do to fix this?