Hey Marius.
When you create your portal aliases, and add more than one, the site will always end up resolving to the topmost alias. So when you move your site from your localhost, to a remote server (or want to access your site from a remote browser), you need to change the order of the portal aliases.
For instance, say you set up your portal aliases in your host settings as follows on your localhost:
http://localhost/mysitehttp://xxx.xxx.xxx.xxx/myvirtualdirectoryhttp://www.mysite.comWhen you move this site to a remote server, before you move it, you should change the order of the aliases, to the following:
www.mysite.com
mysite.com
xxx.xxx.xxx.xxx
localhost/mysite
That will solve the problem for ya. You can also do this directly in the tables (that's what I do), by editing the portal_aliases table in DNN, using Enterprise Manager for 2000 (assuming SQL 2K). For SQL2K5 you need to go into query manager.
Hope this helps.