Excel 2003 routine fails in Excel 2007 - Label autosize issue

[AlexanderBB]

Can anyone suggest a fix or workaround, please?
In Properties label1 Autosize= True, Len = 250, Wordwrap = True
Font is ms sans serif, 8, not Bold.

Sub stringtest2()

Dim LongString As String, LabelWidth As Long, ListHeight As Long
Dim NextSpacePosition As Integer, PreviousPlace As Integer, Done As Boolean

LongString = [Any text about 70 chars+ with space(s)]
UserForm3.ListBox1.Width = 250

Do
    UserForm3.Label1 = LongString
    LabelWidth = UserForm3.Label1.Width
    If LabelWidth > 250 Then
            Do
                PreviousPlace = NextSpacePosition
                NextSpacePosition = InStr(PreviousPlace + 1, LongString, " ")
                UserForm3.Label1 = Left(LongString, NextSpacePosition)
            Loop Until UserForm3.Label1.Width > 250
            'UserForm3.ListBox1.AddItem Left(LongString, PreviousPlace)
            LongString = Mid(LongString, PreviousPlace + 1)
            NextSpacePosition = 0
        Else
            Done = True
    End If
Loop Until Done
'UserForm3.ListBox1.AddItem LongString

ListHeight = UserForm3.ListBox1.ListCount * 10
UserForm3.ListBox1.Height = ListHeight
UserForm3.Show vbModeless
End Sub

I've remmed out the .Additem list bits as they're not affected. The label is the problem, in Excel 2003 it will resize to the right length
i.e. whatever text is assigned to it, but Excel2007 stays at a set width and never changes.