If you moved your site and database from your local machine to a server, it would be very easy to get a lot of 404 errors if the url structure was not the same on the local machine as on the server. You gave no example of the urls that produce a 404.
http://www.mojoportal.com/moving-an-installation-of-mojoportal-to-a-different-server.aspx
Other than that it should work. It works for me and no-one else is reporting any problem with it.
You did not mention what version of mojoPortal, OS/hosting environment.
Hope it helps,
Joe