Index: wp-includes/comment.php
===================================================================
--- wp-includes/comment.php	(revision 19727)
+++ wp-includes/comment.php	(working copy)
@@ -1796,7 +1796,7 @@
 	// Parsing the post, external links (if any) are stored in the $post_links array
 	// This regexp comes straight from phpfreaks.com
 	// http://www.phpfreaks.com/quickcode/Extract_All_URLs_on_a_Page/15.php
-	preg_match_all("{\b http : [$any] +? (?= [$punc] * [^$any] | $)}x", $content, $post_links_temp);
+	preg_match_all("{\b https? : [$any] +? (?= [$punc] * [^$any] | $)}x", $content, $post_links_temp);
 
 	// Step 2.
 	// Walking thru the links array