Try the following steps

1. create a local user on the console where u want to run the job.

2.Add him into local administrator group.

3.Grant him the job "log on as a batch job" from local security settings.

4.Try to create a database user with the same name.

5.Now on OEM grant the preffered credentials to this user both on the database and node.

6.Try to restart the oracle Intelligent agent.

Now u can able to start any batch process on OEM console.

all the best

regards

akhadar