Hi Daniele,
I tried loading a PDF from the applications localfolder using your code and it seems to work OK (even with a nag screen). I’m using the latest version which you can test below:
http://prerelease.componentone.com/hotfixes/winrtxaml/C1WinRTXAML_8.0.20132.342_RC1.msi
Let me know if this works for you. If it doesn’t then maybe the way you create or access the files is different than what i’ve tested.
Thanks
Greg