Logon Script Weirdness - Vista Systems

Hello All,

I have a logon script (W2k3 domain) which runs as part of a group policy.
The script connects a networked printer and sets it as default. Works
perfect on Windows Xp systems. Just introduced 4 Vista Pro systems to the
network. I'm findng the script runs and connects the printer, but setting it
as the default is hit and miss! Sometimes it sets it as default, other times
not. The VBS script is as follows:

Option Explicit
Dim objNetwork, strUNCPrinter
strUNCPrinter = "\\server1\laser7"
Set objNetwork = CreateObject("WScript.Network")
objNetwork.AddWindowsPrinterConnection strUNCPrinter
objNetwork.SetDefaultPrinter "\\server1\laser7"
WScript.Quit

Anyone have any suggestions? It would be greatly appreciated!!!