MRBS shows fatal error and stops the cron job. Moodle can't run the cron job completely.

Server Time: Sun, 19 Feb 2012 13:38:23 +0100

Created missing context instances
Cleaned up stale user sessions
Running auth crons if required...
Running enrol crons if required...
Starting activity modules
Processing module function quiz_cron ...Starting quiz reports
Finished quiz reports
Starting legacy quiz reports
Finished legacy quiz reports
... used 2 dbqueries
... used 0.0027060508728027 seconds
done.
Finished activity modules
Starting blocks
Processing cron function for mrbs....
Fatal error: [] operator not supported for strings in
/Library/Server/Web/Data/Sites/Default/moodle/blocks/mrbs/import.php on line 52