Unable to call sp_start_job from website only I have an agent job that I'm trying to use to kick off an SSIS package via a web page. I have configured my web site running in an application pool as user X. 

When I invoke sp_start_job as use X from SSMS it successfully starts the job.

When I use my web page to invoke sp_start_job permission is denied.

They user is an administrator locally, and a member of the sysadmin role.

What is preventing successfully invoking sp_start_job from the website?
Can you confirm with a Profiler trace which credentials are attempting to execute sp_start_job? I'm curious if it's the credentials of the client using the browser or the underlying application pool. If the account in question has sysadmin, it should already have the permissions to execute jobs.