Cron dies, why ?

[Christer Bernerus]

We're still running 4.1 BSD in a VAX11/780, for some strange reason
cron dies silently. This seems to be correlated with how heavy the
machine is loaded. I made a changed version that didn't fork, and thus
obtained a dump. This showed that cron got a segmentation fault in
malloc that was called from realloc on line 168 in cron.c.

Has anybody experienced this before ?