>Don't know what you're storing in ViewState, but my understanding is the web generally works in lower case (recommended or required in various HTML/XHTML etc. specs) and browsers automatically do some lowercasing e.g.
http://en.wikipedia.org/wiki/URL_normalizationI am not doing anything. This is all the default behavior. This ViewState is stored in uppercase. But, for some kind of reason, something is hitting the server and once it tries to post, I see that it changes the ViewState and any URL in it to be in lowercase. Thus, the encryption doesn't work anything when ASP.NET tries to decrypt it.