Loopback requests fail


I can’t open URLs of this type:

Firefox shows “Unable to connect” while IE8 shows “Internet Explorer cannot display the webpage”

However when I go to Firewall Behavior Settings → Alert Settings and untick “Enable alerts for loopback requests” it works fine. Network security policy is set to “web browser” for both browsers.

System: Windows XP SP2 (administrators account)
Firewall version: 3.13.126709.581
Defense + : turned off
Comodo AV : not installed