Tandy XENIX 3.01.02 cron sudden death

[jrb at petro.UUCP]

We have had problems with the cron daemon summarily taking unexplained
vacations.  Local authorities are stumped, the cunning crontab crook comes 
creeping under curious circumstances, usually when the machine has been up
and running for some period of time.  Although the existing cron daemon can
be killed and a new one restarted but I personally prefer to re-boot the
computer to solve the problem.  "Death of a cron run" occurs infrequently,
but it is terribly frustrating.  If anyone has solved this problem or at least
experienced it, please let me know.