"mismatch_cnt is not 0" errors generated by weekly cron script on RHEL 5

Issue

• "mismatch_cnt is not 0" errors generated by weekly cron script
• The weekly cron script "99-raid-check" keeps coming up with the error "mismatch_cnt is not 0".
• Is there something wrong with our Software RAID-1 volumes?
• It's not always the same device and it's happening on many of our systems suddenly.
• Two hard drives mirrored and raid-check complains of mismatch_cnt.
  • We have several blades that are in this state.
  • Can we force them to resync without risks?
• Example

/etc/cron.weekly/99-raid-check:

        WARNING: mismatch_cnt is not 0 on /dev/md1