ulimit problem

I have a machine which is producing a 'ulimit' error. I have a user named
patrol that is supposed to be able to run a job. Whenever I 'su - patrol' I
get the error:

    ulimit: cannot raise limit: Operation not permitted

The ulimit command seems pretty terse and I am not sure who or what might be
trying to change the ulimit. Has anyone seen an error lime this before?

Brian Simper