I cannot access www.lubuntu.net from my Macbook Pro running OS X 10.6.8. I have an idea as to what the problem is (see my opinion), but I did all the usual things anyway (see basic troubleshooting), just to check.
I can access almost any other site from my macbook (for example this one). I can access lubuntu.net from my other laptop which is on the same wifi, meaning it's not a network, ISP, or router issue. Also the site is up, and this issue is persistent for several days.
I can successfully ping the site. The site resolves to an IP (thus not a DNS issue). The problem occurs using three different browsers - Chrome, Firefox, Safari. I never use Safari, so it's not an extension issue, either. I cannot access the site even if I paste its IP into the address bar.
My IP is likely not banned, since (1) there is no reason to ban me and (2) my other laptop is able to access the site over the same network, going through the same router.
Rebooting does not solve the issue.
I installed (and quickly uninstalled) a program called PeerGuardian, which blocks "suspicious" IPs. It is mainly used for blocking unwanted peers when downloading torrents. I think that it messed with one of the config files to block the Lubuntu site.
Which files should I check? I've taken a look at /etc/hosts, and that looks fine. Also /etc/resolv.conf looks normal. No idea where to go from here.
EDIT: Here are the contents of system.log for my most recent attempt:
Oct 18 21:44:11 albatross com.avast.proxy: Error reading receive buffer: read(): Connection reset by peer
Oct 18 21:45:20 albatross com.avast.proxy: Defective HTTP request!
Oct 18 21:45:20 albatross com.avast.proxy: Unexpected AV CHECKURL response code (501)!
Oct 18 21:46:24 albatross [0x0-0x165165].com.avast.AAFM: 18 Oct 21:46:24 ntpdate: no servers can be used, exiting
Oct 18 21:46:27 albatross avast!: event_master_disconnected
Oct 18 21:46:38 albatross com.apple.launchd.peruser.501 (com.avast.helper): Throttling respawn: Will start in 5 seconds
Oct 18 21:46:45 albatross com.avast.proxy: Error reading receive buffer: read(): Connection reset by peer
Do you think this is a problem caused by Avast? But I installed avast after the problem started, because I thought it might be a virus, so that doesn't make much sense...
EDIT 2: added contents of /etc/hosts below
## # Host Database # # localhost is used to configure the loopback interface # when the system is booting. Do not change this entry. 127.0.0.1 localhost 255.255.255.255 broadcasthost ::1 localhost fe80::1%lo0 localhost