I made a local backup of a Joomla site a few months ago to test changes before updating the live site. Everything worked fine. Today I checked the local version after a while but when I open the backend (/administrator) it takes a while until the site is loaded. I tried out different things and accidently disconnected my Network Connection. After that everything loads as fast as before. But when I connect the Network Connection the problem reappears. I am running Joomla 1.5.14 on XAMPP 1.7.0.