Just remove the calls to the Fix() method:
If (m.Msg = WM_HSCROLL OrElse m.Msg = WM_VSCROLL) AndAlso ((CInt(m.WParam) And &HFFFF) = 5) Then
' Change SB_THUMBTRACK to SB_THUMBPOSITION
m.WParam = CType((CInt(m.WParam) And (Not &HFFFF)) Or 4, IntPtr)
End If