CRON runs things twice

[Chris Rende]

(Nixdorf Targon M35/50 TOS 3.2 --> Pyramid 9810 OSx 4.0)

On rare occaisions ATTCRON is running things twice apparently because it
does things early. (System V Release 2 CRON)

Here is a section from my cron's log:

>  CMD: /etc/dmesg - >>/usr/adm/messages
>  root 15896 c Sat Feb 10 06:49:59 1990
<  root 15896 c Sat Feb 10 06:50:00 1990
>  CMD: /etc/dmesg - >>/usr/adm/messages
>  root 15898 c Sat Feb 10 06:50:00 1990
<  root 15898 c Sat Feb 10 06:50:00 1990

Here is the associated crontab entry:
00,10,20,30,40,50 * * * * /etc/dmesg - >>/usr/adm/messages

What seems to be happening is that CRON is not calculating a long enough
delay time before running an entry.

Maybe it's an oddball rounding error that causes the calculation to
come up short... ?

If CRON would add another .5 seconds to each delay time then there
probably wouldn't be a problem.

Has anyone else observed this behaviour?
Is it a known bug?
Is there a fix?

car.
-- 
Christopher A. Rende           Central Cartage (Nixdorf/Pyramid/SysVR2/BSD4.3)
uunet!edsews!rphroy!trux!car   Multics,DTSS,Unix,Shortwave,Scanners,StarTrek
 trux!car at uunet.uu.net         Minix 1.2,PC/XT,Mac+,TRS-80 Model I,1802 ELF
       "I don't ever remember forgetting anything." - Chris Rende