It worked fine with the same ISP earlier this month, and the very same sites work outside the local network (same ISP, but not the same computer then). IE, Netscape or Firefox result in the same situation happening. To the best of my knowledge, there is nothing fishy in the local network that would lock down ports, but that only means my knowledge is not adequate here.
I guess I should start setting up a cult for the followers of PBEM. At least, hosting a PBEM game is much easier than attempting to host something based on a site you cannot reach.
