In some environments it has been reported that the next run date is not being updated following a successful execution of some schedules. This causes the schedule to fire over and over again.
Additional code and checks have been put in place to rectify this issue. The problem has been resolved in the latest build.
All users are encouraged to upgrade immediately to the very latest build (Build 20050913 or above)in order to resolve this problem if you already have it or avoid the possibility of it if you haven't yet experienced it.