From: mike on

I have an ASP.NET 3.5 site that talks to ASP.NET 3.5 webservices
the site and the webservices live on different machines

the web side of things has the timeout set to 20 minutes in the
web.config
<forms loginUrl="Login.aspx"
protection="All"
timeout="20"
name="CSCPRS"
requireSSL="false"
slidingExpiration="true"
defaultUrl="ReporterIntro.aspx"
cookieless="UseCookies"
enableCrossAppRedirects="false"/>
</authentication>

the people I did the application for want the timeout upped to 40
minutes
when I changed the value from 20 to 40 the application throws an error
after 20 minutes but it's not exactly a timeout

"Validation of viewstate MAC failed"

with the timeout set to 20 minutes or less everything works fine

is this the case where the web side is not timing out but the web
service are or something along those lines?

How can I increase the timeout to 40 minutes

thanks
mike