Problem with the Restricted Policy in VSTO on Some Objects
A developer was having a hard time using the XML serialization object with VSTO. This thread in google http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&th=289d6c7d97061702&seekm=OUZ%24Kl%24sDHA.4056%40TK2MSFTNGP11.phx.gbl&frame=off discusses how to resolve the issue.
I point it out because I think its important to realize that some objects (though few) might create this type of issue for you in your own VSTO development. Peter Torr also discusses the problem and security in general in his blog entry . I consider this mandatory reading for any VSTO developer.
The other thing I have to say is that the workaround can be nasty (shelling out to CASPOL). Does anyone know if this is addressed better with VSTO 2?