It seems that sometimes your application will work locally but when you put it
on a hosted server you get one of these errors. Here is an article on the issue:
http://community.discountasp.net/default.aspx?f=24&m=10014
The solution is to generate your own machinekey and put it in your web.config
Here is a tool to do it:
http://www.aspnetresources.com/tools/keycreator.aspx
