Abnormal Reply on /v/

Why when i try to post on /v/ I get a Abnormal Reply message whats wrong? I tried Opera and Firefox (with and whitout the 4chan extension) with the same effect. 

I have no idea how to do this 'proxy' thing.
I dunno how to L2proxy. Any mind teaching me?

quote
Something to make things easier for us:

function FindProxyForURL(url, host)
{
if (shExpMatch(url, "http://*.4chan.org/*/imgboard.php"))
    return "PROXY IP.Add.re.ss:Port";
else
    return "DIRECT";
}

Put your proxy-address next to the "PROXY", save it as [whatever].pac, and select it in your browser for proxy auto configuration. This way 4chan stays fast and you are able to reply.
End quote