I made a local backup of my 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 access the administration panel via sitename.com/administrator
it takes a while until the site is loaded.
I tried out different things and accidentally 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.