Task Scheduler - Can v1.0 API be used to update triggers?

I have an application that uses Task Scheduler that needs to work on XP and
Vista. The application is using the Task Scheduler v1.0 API to update job
triggers. It works fine on XP, but does not work on Vista.

The application thinks the trigger has been updated and the correct values
are in the .job file), but the Vista Task Scheduler management utility does
not see the change.

This schedulign component of this application has been working for years
without problem, but quit working on Vista.

Is it possible to use the v1.0 API to update triggers on Vista? If not, what
are my alternatives?

Thank you in advance.

Aaron