Index: wp-includes/comment.php
===================================================================
--- wp-includes/comment.php	(revision 6667)
+++ wp-includes/comment.php	(working copy)
@@ -552,7 +552,7 @@
 	extract($commentdata, EXTR_SKIP);
 
 	if ( ! isset($comment_author_IP) )
-		$comment_author_IP = preg_replace( '/[^0-9a-fA-F:., ]/', '',$_SERVER['REMOTE_ADDR'] );
+		$comment_author_IP = preg_replace( '/[^0-9a-fA-F:.]/', '',$_SERVER['REMOTE_ADDR'] );
 	if ( ! isset($comment_date) )
 		$comment_date = current_time('mysql');
 	if ( ! isset($comment_date_gmt) )
@@ -650,7 +650,7 @@
 	$commentdata['comment_post_ID'] = (int) $commentdata['comment_post_ID'];
 	$commentdata['user_ID']         = (int) $commentdata['user_ID'];
 
-	$commentdata['comment_author_IP'] = preg_replace( '/[^0-9., ]/', '',$_SERVER['REMOTE_ADDR'] );
+	$commentdata['comment_author_IP'] = preg_replace( '/[^0-9a-fA-F:.]/', '',$_SERVER['REMOTE_ADDR'] );
 	$commentdata['comment_agent']     = $_SERVER['HTTP_USER_AGENT'];
 
 	$commentdata['comment_date']     = current_time('mysql');