I checked all the configuration of the server, everything seems fine ! I also have this problem when I try to upload a file in the attachments !
the error in my logs :
Code:
[Sun Aug 15 16:44:59 2010] [error] [client 41.224.171.198] Premature end of script headers: newattachment.php, referer: http://board.mysite.com/newattachment.php?p=10043&editpost=1&poststarttime=1281883477&posthash=a31b8734163790ee2ed8c485eacaeb94