Take a look at the settings in the Web.csproj file. If you open it in notepad (or upload it to the solution and right-click, edit ...), you can see the VisualStudio settings. I assume that you may need to update these settings.
Here are the settings for one of my SL projects that run from the local host.
<VisualStudio> <FlavorProperties GUID="{349c5851-65df-11da-9384-00065b846f21}"> <WebProjectProperties> <UseIIS>False</UseIIS> <AutoAssignPort>True</AutoAssignPort> <DevelopmentServerPort>52878</DevelopmentServerPort> <DevelopmentServerVPath>/</DevelopmentServerVPath> <IISUrl>http://localhost/ExternalWeb</IISUrl> <NTLMAuthentication>False</NTLMAuthentication> <UseCustomServer>False</UseCustomServer> <CustomServerUrl> </CustomServerUrl> <SaveServerSettingsInUserFile>False</SaveServerSettingsInUserFile> </WebProjectProperties> </FlavorProperties> </VisualStudio>
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