Job failing

I have a scheduled job on a SQL 2000 database which is failing. Here is the error message :

The job failed. Unable to determine if the owner (caci\snasir) of job Integrity Checks Job for DB Maintenance Plan 'IDS' has server access (reason: Could not obtain information about Windows NT group/user 'caci\snasir'. [SQLSTATE 42000] (Error 8198)).

I am the SA on the instance. I wonder why would I be getting this error message? I am able to logon to this instance and browse and change things. So clearly it recognizes me. But when I run the job it fails. Wonder why? my SQL Server version is 8.0.

The Job is owned by [caci\snasir]. The error indicates that SQL Server cannot validate [caci\snasir] credentials.

It may be better to transfer the job ownership to [sa].