Textbox problem

In my program I have a routine that selects all text in a textbox when it gets the focus (optional).
This doesn't work with TextBoxW so very well.

Code:
Private Sub TextBoxW1_GotFocus()

With TextBoxW1
.SelStart = 0
.SelLength = 999
End With

End Sub
The effect is, that the text gets selected from the start to the clicked point.

The intrinsic textbox doesn't show this behavior.
The text gets completely selected as intended.