I just had this error on my prosper202, it seems an update or something with MySQL caused the table to crash and I could not find a solution anywhere so I am posting this for anyone who has this issue in the future.
SELECT COUNT(*) FROM 202_cronjobs WHERE cronjob_type='secon' AND cronjob_time='1373633941' Table './yourdb_yourdb/202_cronjobs' is marked as crashed and should be repaired
Simply go to your WHM or whatever your servers admin panel is and start the “Repair a MySQL Service”.
This should fix the crashed table. I know it seems simple but I didn’t know wtf to do at first.
Hope this helps someone!