I just got caught again!
The inline code (for the first of 8 checkboxes on my GUI form) works fine
<pre> Select Case strValue
Case "True"
Me.cbRO.Value = True
Case "False"
Me.cbRO.Value = False
Case Else
Me.cbRO.Value = Null
End Select</pre>

So I write and call a little procedure
<pre> Call SetABit(strValue, Me.cbRO)

Function SetABit(strValue As String, cb As CheckBox)
Select Case strValue
Case "True"
cb.Value = True
Case "False"
cb.Value = False
Case Else
cb.Value = Null
End Select
End Function</pre>

Which bombs "Run-time error 13 Type Mismatch", with no yellow line showing me where we are
(but I can guess!)

I have to distinguish between a CheckBox that is a Word object, and a checkbox which is an object
on a GUI userform:

<pre>Function SetABit(strValue As String, cb As MSForms.CheckBox)
Select Case strValue
Case "True"
cb.Value = True
Case "False"
cb.Value = False
Case Else
cb.Value = Null
End Select
End Function</pre>