Hi Al,
This error is happening in the ASP.NET Enterprise Manager at your host, it has nothing to do with mojoPortal or the mojoportal sql script so I'm not really the support person for that. However, it is a common error in general in ASP.NET applications. The answer to fix it is right in the message:
"Description: Request Validation has detected a potentially dangerous client input value, and processing of the request has been aborted. This value may indicate an attempt to compromise the security of your application, such as a cross-site scripting attack. You can disable request validation by setting validateRequest=false in the Page directive or in the configuration section. However, it is strongly recommended that your application explicitly check all inputs in this case."
You have to modify either the web.config or the page directive in your ASP.NET Enterprise Manager to get it to work.
More info here:
http://www.asp.net/faq/requestvalidation.aspx
Or just google for asp.net requestvalidation
Hope it helps,
Joe