--- scorm_12lib.php	Fri Nov 16 10:58:52 2007
+++ scorm_12lib.php	Mon Dec 17 19:20:09 2007
@@ -193,6 +193,7 @@
         // Retrieve user tracking data for each learning object
         // 
         $usertracks = array();
+ $prerequsertracks = array();
         foreach ($scoes as $sco) {
             if (!empty($sco->launch)) {
                 if ($usertrack=scorm_get_tracks($sco->id,$user->id,$attempt)) {
@@ -200,6 +201,11 @@
                         $usertrack->status = 'notattempted';
                     }
                     $usertracks[$sco->identifier] = $usertrack;
+ $prerequsertracks[$sco->identifier] = $usertrack;
+ } else {
+ // set default 'notattempted' status for scoes have never been seen.
+ $usertrack->status = 'notattempted';
+ $prerequsertracks[$sco->identifier] = $usertrack;
                 }
             }
         }
@@ -253,8 +259,8 @@
             }
             $nextsco = next($scoes);
             $nextisvisible = false;
-            if (($nextsco !== false) && ($optionaldatas = scorm_get_sco($nextsco->id, SCO_DATA))) {
-                if (!isset($optionaldatas->isvisible) || (isset($optionaldatas->isvisible) && ($optionaldatas->isvisible == 'true'))) {
+            if (($nextsco !== false) && ($nextoptionaldatas = scorm_get_sco($nextsco->id, SCO_DATA))) {
+                if (!isset($nextoptionaldatas->isvisible) || (isset($nextoptionaldatas->isvisible) && ($nextoptionaldatas->isvisible == 'true'))) {
                     $nextisvisible = true;
                 }
             }
@@ -326,8 +332,7 @@
                             $previd = $sco->id;
                         }
                     }
-                    if (empty($sco->prerequisites) || scorm_eval_prerequisites($sco->prerequisites,$usertracks)) {
-                        if ($sco->id == $scoid) {
+                    if (empty($optionaldatas->prerequisites) || scorm_eval_prerequisites(stripslashes($optionaldatas->prerequisites),$prerequsertracks)) {                        if ($sco->id == $scoid) {
                             $result->prerequisites = true;
                         }
                         $url = $CFG->wwwroot.'/mod/scorm/player.php?a='.$scorm->id.'&currentorg='.$currentorg.$modestr.'&scoid='.$sco->id;
--- scormlib.php	Wed Jan 17 10:02:26 2007
+++ scormlib.php	Mon Dec 17 19:32:55 2007
@@ -462,10 +462,6 @@
     
         $xmltext = file_get_contents($manifestfile);
 
-        $pattern = '/&(?!\w{2,6};)/';
-        $replacement = '&';
-        $xmltext = preg_replace($pattern, $replacement, $xmltext);
-
         $objXML = new xml2Array();
         $manifests = $objXML->parse($xmltext);
 //print_object($manifests);