Loading XPS file into DocumentViewer

Hi,

I'm trying to load one XPS file without success:

Dim document As New XpsDocument("c:\puesto\prueba.xps", FileAccess.Read, Packaging.CompressionOption.NotCompressed)

Dim fixed As FixedDocumentSequence = document.GetFixedDocumentSequence

visorXPS.Document = document

Primary platform is Windows 7 Ultimate 64 bit along with VS 2012/Sql2k8 for WPF/SilverLight projects.