I need some help understanding how principal works. Rather than just let the user sign up for an account I've created an email confirmation that basically creates a random string puts it in the db and sends that string to the user in a link back to my site with the code as a variable in the querystring http://mysite.com/modules/user/verif...px?code=123454 whats happening is after they've hit the registration it takes to confirmation page that says check your email. if the user then checks the email it opens the link in a new browser window and returns an error with the link to the site header on my LOCAL drive:
"Specified Cast is not valid..." "Controls.User.SiteHeader.Page_Load(Object sender, EventArgs e) in [MY LOCAL DRIVE WHERE FILE EXISTS]\controls\user\siteheader.ascx.cs:34"

Line 34 reads:
If I then copy and paste the link from the email into the browser that I began the registration process in, it continues as it should. I think this has something to do with it using my windows account as the identity but I dont know how to fix. Thanks.

There must be over 50 messages here about the "specified cast is not valid" issue. Please read the past messages.