Daily scheduled job has its schedule disabled despite successful completion

I have a job which is scheduled to run once daily. The job is enabled and the schedule is also enabled. After the job runs (successfully), the schedule has its 'Enabled' flag reset (i.e. the 'Enabled' checkbox in the schedule properties has become unchecked) and so is not rescheduled.

I have other jobs configured in a similar way, but they are run and then rescheduled in the normal way without any problems.

What could be going on?I'm sure you'd know but there is definately no disables step in the job?
e.g
EXEC sp_update_job @.job_name = 'bla bla',
@.enabled = 0|||This may be of some use to you. Have you checked the logs?

http://support.microsoft.com/default.aspx?scid=kb;en-us;295378&Product=sql2k