Logrotate skips a log number

[Anthony Simonelli <asimonelli7@yahoo.com>]

For some reason, my logrotate script skips a number
every week.  As you can see, the date is sequential
but the name of the file skipped one.  I'm not losing
any logs but I would like to know why it names it like
this.  Any idea why?

2006-06-02 09:53 /var/log/mail.log
2006-06-02 03:30 /var/log/mail.log.0.gz
2006-06-01 03:30 /var/log/mail.log.1.gz
2006-05-31 03:30 /var/log/mail.log.2.gz
2006-05-30 03:30 /var/log/mail.log.3.gz
2006-05-29 03:30 /var/log/mail.log.4.gz
2006-05-28 03:30 /var/log/mail.log.5.gz
2006-05-27 03:30 /var/log/mail.log.7.gz
2006-05-26 03:30 /var/log/mail.log.8.gz

The Logrotate script:

/var/log/mail.log {
   daily
   missingok
   start 0
   rotate 28
   compress
}