This sounds very familiar to another thread, but I didn't want to hijack it (as it was a couple of months old), so I thought I would start a new thread.
My problem is that the Zimbra stats service runs for a period of time (days, up to a week or so) and then stops. I started a cron job to check the server status every 15 minutes so I could pin point when it stopped to give me a better area to look in the logs.

The following is from /var/log/zimbra.log, but it doesn't give much insight:
zimbramon[30939]: 30939:err: Service status change: stats changed from running to stopped

In the other thread, someone asked what was in /opt/zimbra/zmstat/zmstat.out and the answer is not much. There are no timestamps so I can't pin down any dates, but most of the lines in any of my zmstat.out.*gz files is similar to the following:
Use of uninitialized value in addition (+) at /opt/zimbra/libexec/zmstat-allprocs line 193.
Similar since the line number varies a bit (193, 197 and 198 seem to be very predominant).
There is one other line in the zmstat.out.2.gz file (this file corresponds to the date/time that my cron job indicated the stats stopped) :
ppid not found for 30708 at /opt/zimbra/libexec/zmstat-convertd line 57.

Any clues?