Deployed Silverlight - Can only use localhost rather than the URL

[ShaningYu]

For a SL project that runs well in debugging, I followed the procedure: 39169 - Deploy a Silverlight application to IIS 6.0 and 7.0‌, and copied the needed file to server's inetpub\wwwroot\.  In IIS7, if I right-click the application to get the page as http://localhost/myApp/myApp.html, everything works file.  However, after I change the localhost to the URL, the page displays well only in its stating stage.  When I run the query, I got a plenty of errors like that

Locator service failed: System.Security.SecurityException ---> System.Security.SecurityException: security error

at System.Net.BrowserHttpWebRequest.InternalEndGetResponse(IAsyncresult asyncResult)

at System.Net.BrowserHttpWebRequest ...

I realize that this application can't be Converted to Application in IIS Manager.  When I tested the settings, I received the error: Invalid application path.  How can this problem be solved?  Thanks.

[ShaningYu]

By referring to the procedure: http://stackoverflow.com/questions/7939693/iis-7-invalid-application-path-win-7 , I created a Virtual Directory in IIS7.5 Manager's Web Sites, and then set the Physical Path.  The project was got deployment.  However, I still can't run the query if the page uses URL address rather than localhost.  In this server, there are other multiple applications that have no problem using URLs.  Any suggestion for this problem?  Thanks.

[ShaningYu]

Had a communication w/ a professional.  He said the problem was not due to the security or cross domain issue.  The problem was that the IP address was not recognized.  Then, I changed the http://IPAddress/MyApp to http://myComputerName/MyApp.  The errors were gone.  What settings should I do in order to use IP address in this application?  Thanks.