In a maintenance plan, can specify how many days to keep
backup files for a database backup.  Backup files older
than that number of days are deleted.  A couple of times
of the past 2 years this automatic deletion function has
seemingly turned itself off.  The only way I could remedy
this was to make some change to the maintenance plan and
re-save.  Then the automatic deletion would work again.

A week ago this happened and I re-saved the maintenance
plan which remedied the situation.  However, today I
noticed that of the 12 databases being backed up, only 9
had their "old" backup files automatically deleted.

This SQL Server is v7.0 with SP3 running on Win 2000.  

Any ideas on this?