I reported this problem in MDL-10815, thinking it was related to SCORM. Today, another user (Robert Duncan) reported the same problem in http://moodle.org/mod/forum/discuss.php?d=78587. In both cases, we are restoring a course into a new empty course. Duplicate resource/activity icons are created with no text (see screenshot). In both cases, no third-party modules were involved. In my case, the restore was from another course backed up on the same 1.8.2 site. In my case, there was an error at the end of the restore "An error has occurred and the restore could not be completed!" but the new course was left in the corrupted state shown. I'm not sure if Robert Duncan received this message (it came at the very end of the restore log and would be easy to ignore).