When working with scheduled agents, we often tend to run the agent by right clicking it and clicking on run or calling it on a button click before we schedule it. It may not work always, cos scheduled agents will have a lot of issues that are not associated with a normal agent which may run properly with your security permissions when you run it.
For example you may have a role enabled for you on the ACL where as your server may not.
So Scheduled when they run automatically will run with server rights over the database and hence may result in different results.
So the best way I know to test the working of a scheduled agent is by running it through the following command,
Tell Amgr Run "DatabasePath" 'AgentName'
Mind the usage of the single and the double quotes. They must not be changed.
Hope this helps :)