I have been getting reports about problems with our 4.0 .NET build of mojoportal 2.4.0.4 so since Aruba does not have 4.5 I do not recommend upgrading to mojoPortal 2.4.0.4 at any Aruba hosting. Also I would not install a second copy in a sub folder as that leads to conflicts with web.config files.
You are still having the same problem with a skin but other skins work? Then you can email me the skin and I will try to fix it for you.