Index: typo3/sysext/cms/tslib/class.tslib_menu.php
===================================================================
--- typo3/sysext/cms/tslib/class.tslib_menu.php	(revision 6054)
+++ typo3/sysext/cms/tslib/class.tslib_menu.php	(working copy)
@@ -807,13 +807,20 @@
 					$sys_language_uid = intval($GLOBALS['TSFE']->sys_language_uid);
 				} else $sys_language_uid=0;
 
-				$selectSetup = Array(
-					'pidInList'=>$this->id,
-					'orderBy'=>$altSortField,
-					'where' => 'colPos=0 AND sys_language_uid='.$sys_language_uid,
-					'andWhere' => 'sectionIndex!=0'
-					);
-				switch($this->mconf['sectionIndex.']['type'])	{
+				$sectionIndexSelectWhere = 'colPos = 0 AND sys_language_uid = ' . $sys_language_uid;
+					// modify the default "where" clause for the sectionIndex option
+				if ($this->mconf['sectionIndex.']['where'] || $this->mconf['sectionIndex.']['where.']) {
+					$sectionIndexSelectWhere = $GLOBALS['TSFE']->cObj->stdWrap($this->mconf['sectionIndex.']['where'], $this->mconf['sectionIndex.']['where.']);
+				}
+
+				$selectSetup = array(
+					'pidInList' => $this->id,
+					'orderBy'   => $altSortField,
+					'where'     => $sectionIndexSelectWhere,
+					'andWhere'  => 'sectionIndex != 0'
+				);
+
+				switch ($this->mconf['sectionIndex.']['type']) {
 					case 'all':
 						unset($selectSetup['andWhere']);
 					break;