[AccessD] You canceled the previous operation (but I didn't)

Dear List:
 
Can anyone see why I should get an error "2001 - you cancelled the previous
operation" on the statement Me.Bookmark = Me.RecordsetClone.Bookmark in the
following?

 
    Me.RecordsetClone.FindFirst "[PartNumber] = '" & Me.cboPartsList.Value &
"'"
    MsgBox Me.RecordsetClone.NoMatch
    If Me.RecordsetClone.NoMatch = True Then
        MsgboxUni Me.hWnd, TranslateMsgbox("PartNumberNotFound"), ,
vbExclamation
        DoCmd.GoToRecord , , acFirst
    Else
        Me.Bookmark = Me.RecordsetClone.Bookmark
        'Me.cmdExitDemandSide.SetFocus
        'cboPartsList.Visible = False
    End If

Interestingly, if I hit debug to the error message (and it opens the code
page with that statement highlighted) and I pressF5, it carries on just
fine.
 
 
MTIA,
 
Rocky