Thank you very much! Now it's proven that you and me are able to access the storeadmin from different countries, both using mobile connection. My client says, that it is going slowly at this moment. But i draw the conclusion that it has nothing to do with your template or even with virtuemart. Only the google font js is a little bit suspect in my eyes. Maybe, with what reason ever, client's computer (firewall, he uses norton secuirity) is blocking these files or just one file. Nevertheless, this thread is solved and can be closed.
Now i have two solved threads. And your reaction was fast and competent. For this i say Thank You! eCommerce is a great solution for virtuemart, because of the nice features and the possibility of much customization.
Best regards.
Michael