Hello.  I am attempting to use a Web Service to create scheduled tasks.  This
works locally, on a workstation running XP, but when I move the web service,
or a standalone application to a W2003 server, and attempt to create
Scheduled Tasks, nothing happens.

I have been researching.  I ran across a reference to Action Control Lists
and Web Services, dealing with the Microsoft Commerce Service.  
Specifically, granting full control with the cacls command.
cacls tasks /e /g <data_domain_name>\MarketingWebSvc:f,

Also, looking on some MSDN pages, it appears that the Web Services are by
default created with least privileges, so as to avoid exploitation.