This has been an ongoing issue. I have had this problem before. From what I can recall. Usually after a fresh install, the first cron.weekly to run, this error will show up...Which then each following cron.weekly will not have this error...And also, same as if there is a update to the system...Sometimes during a yum update, no particular one, the cron.weekly error will ocurr. Like i said this has been ongoing, and i recognize this error from years back. I believe it to be harmless and i really wouldnt worry about as I dont.