squid problem

ERROR
The requested URL could not be retrieved

While trying to process the request:

POST /tea/ajax.forum.php?act=state&url=%3Ftrd_id%3D311286%26&frm_id=1 HTTP/1.1
Host: bbs.creaders.net
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.0.4) Gecko/2008102920 Firefox/3.0.4
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: ja,en-us;q=0.8,en;q=0.5,zh-cn;q=0.3
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 300
Proxy-Connection: keep-alive
Referer: http://bbs.creaders.net/tea/bbsviewer.php?trd_id=311286
Cookie: __utmz=51531515.1228498089.25.2.utmcsr=google|utmccn=(organic)|utmcmd=organic|utmctr=creaders.net; __utma=51531515.1001208360004353200.1214275916.1227497917.1228498089.25; __qca=461eef15-63137-e34a5-be10b; __utma=224743241.1420826263048711200.1224658004.1225952701.1228498288.4; __utmz=224743241.1228498288.4.4.utmcsr=creaders.net|utmccn=(referral)|utmcmd=referral|utmcct=/; __qcb=587432554; __utmb=51531515.1.10.1228498089; __utmc=51531515; PHPSESSID=b2acf57ecb46e2021b7a7a5720eb3359; __utmb=224743241.2.10.1228498288; __utmc=224743241
Pragma: no-cache
Cache-Control: no-cache


The following error was encountered:

* Invalid Request

Some aspect of the HTTP Request is invalid. Possible problems:

* Missing or unknown request method
* Missing URL
* Missing HTTP Identifier (HTTP/1.0)
* Request is too large
* Content-Length missing for POST or PUT requests
* Illegal character in hostname; underscores are not allowed

Your cache administrator is root.
Generated Fri, 05 Dec 2008 17:15:54 GMT by tm-mon3.dm-hikari.ad.hikari.co.jp (squid/2.5.STABLE3)
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