Index: backup/restorelib.php
===================================================================
--- backup/restorelib.php	(revision 14386)
+++ backup/restorelib.php	(working copy)
@@ -4844,6 +4844,10 @@
                                            FROM {$CFG->prefix}backup_ids
                                            WHERE backup_code = '$restore->backup_unique_code' AND
                                                  table_name = 'course_modules'");
+
+        if (!$course_modules) {
+            $course_modules = array();
+        }
         if ($course_modules) {
             foreach($course_modules as $cm) {
                 //Get full record, using backup_getids
@@ -4871,19 +4875,10 @@
                 } else {
                     $status = false;
                }
-               // MDL-14326 remove empty course modules instance's (credit goes to John T. Macklin from Remote Learner)
-               $course_modules_inst_zero = get_records_sql("SELECT id, course, instance
-                                           FROM {$CFG->prefix}course_modules
-                                           WHERE id = '$cm_module->new_id' AND
-                                                 instance = '0'");
-                                                 
-                    if($course_modules_inst_zero){ // Clean up the invalid instances
-                         foreach($course_modules_inst_zero as $course_modules_inst){
-                             delete_records('course_modules', 'id',$course_modules_inst->id);
-                         }
-                    }
-
             }
+        /// Remove ones that failed to be remapped
+            delete_records('course_modules', 'course', $restore->course_id, 'instance', 0);
+
         /// Finally, calculate modinfo cache.
             rebuild_course_cache($restore->course_id);
         }
Index: mod/assignment/backuplib.php
===================================================================
--- mod/assignment/backuplib.php	(revision 14386)
+++ mod/assignment/backuplib.php	(working copy)
@@ -44,6 +44,10 @@
     function assignment_backup_one_mod($bf,$preferences,$assignment) {
         
         global $CFG;
+
+        if ($assignment === 0) {
+            return false;
+        }
     
         if (is_numeric($assignment)) {
             $assignment = get_record('assignment','id',$assignment);