I've noticed a few times that after posting a reply to an article, my access to the whole of Slashdot fails. I can't even ping the server.
Yet I can load the page on a separate internet connection (i.e. different IP address), and if I reboot my router to get a new IP.
I'm not sure if this is a bug with the servers, my connection, or some sort of admin thing (my "karma" is positive).