eXtplorer - PHP-based File Manager

I'm using joomla 2.5 with dyndns.org (dynamic ip provider). The server is running on higher ports then the basic (443, 80, 8080) since the internet provider is blocking this.

When i now start extplorer in joomla backend, i get the joomlamenu (top) and the footer of extplorer. But for the rest, the browser is keeping on refreshing.

Any idea what i can do?