Replication Job Failed. Unable to determine the owner

A former employee at my organization created a replication job to back up our database. The developer has since left and his windows account was deleted. I'm now receiving this error:

SQL Server Scheduled Job 'Replication agents checkup' (0xFC17DD4EF8E5694E8B786EE54CF8AD0D) - Status: Failed - Invoked on: 2007-06-05 15:40:00 - Message: The job failed. Unable to determine if the owner (username) of job Replication agents checkup has server access (reason: Could not obtain information about Windows NT group/user 'username', error code 0x534. [SQLSTATE 42000] (Error 15404) The statement has been terminated. [SQLSTATE 01000] (Error 3621)).

How can I fix this? I looked under the Replication folder but didn't see anything.

In Object Explorer, look at the job in SQL Server Agent to see who owns it, and verify the account is valid.

|||That's for the help. I changed the owner but am now getting this error:

SQL Server Scheduled Job 'Replication agents checkup' (0xFC17DD4EF8E5694E8B786EE54CF8AD0D) - Status: Failed - Invoked on: 2007-06-07 01:00:00 - Message: The job failed. The Job was invoked by Schedule 175 (Replication agent schedule.). The last step to run was step 1 (Run agent.).

When I executed the maintenance plan manually it worked, but it doesn't seem to work on the schedule. I've never created a maintenance plans so I'm going to look up some more information to see if I can figure out what is going to wrong.