diff -ur pukiwiki-1.4.7_notb_utf8.org/lib/convert_html.php pukiwiki-1.4.7_notb_utf8/lib/convert_html.php
--- pukiwiki-1.4.7_notb_utf8.org/lib/convert_html.php 2006-10-22 05:41:10.000000000 +0900
+++ pukiwiki-1.4.7_notb_utf8/lib/convert_html.php 2007-09-19 18:35:27.918454900 +0900
@@ -306,7 +306,7 @@

                 $this->tag   = $tag;
                 $this->tag2  = $tag2;
-                $this->level = min(3, strspn($text, $head));
+                $this->level = min(10, strspn($text, $head));
                 $text = ltrim(substr($text, $this->level));

                 parent::insert(new ListElement($this->level, $tag2));
@@ -846,7 +846,7 @@
                         }

                         // Horizontal Rule
-                        if (substr($line, 0, 4) == '----') {
+                        if (preg_match('/^--*$/', $line)) {
                                 $this->insert(new HRule($this, $line));
                                 continue;
                         }