Index: branches/version-2_12-dev/data/class/SC_CheckError.php
===================================================================
--- branches/version-2_12-dev/data/class/SC_CheckError.php	(revision 22592)
+++ branches/version-2_12-dev/data/class/SC_CheckError.php	(revision 22609)
@@ -63,6 +63,10 @@
         $this->createParam($value);
         // HTMLに含まれているタグを抽出する
+        $arrTagIncludedHtml = array();
         preg_match_all('/<\/?([a-z]+)/i', $this->arrParam[$value[1]], $arrTagIncludedHtml);
-
+        // 抽出結果を小文字に変換
+        foreach ($arrTagIncludedHtml[1] as $key => $matchedTag) {
+            $arrTagIncludedHtml[1][$key] = strtolower($matchedTag);
+        }
         $arrDiffTag = array_diff($arrTagIncludedHtml[1], $value[2]);