My network layout is as follows:
A GNU/Linux server acting as router connects to the internet through PPPoE. On a second interface a switch is connected. On this switch 2 computers are connected, a Laptop and a Desktop. The laptop runs Windows XP Professional, the desktop runs Windows Vista. Both backend machines get configured through DHCP running on the GNU/Linux server.
The problem is that the desktop is unable to make a successful connection to certain websites while the laptop is able to connect to these sites. If I hook up the laptop to the cable attached to the desktop it is still able to connect to those sites, so it is not the cable.
One of the sites the desktop is unable to connect to is FAIL Blog. It keeps on loading, and never finishes. It does download the main HTMLpage, but it stales completely on the http://s2.wordpress.com host which serves some of the files. It appears to be mostly related to CDN hosts.
It doesn't matter which browser I use. And there is no special firewall software running on the desktop. The hostnames resolve as they should.
Does anyone have an idea what could be the cause of this problem?