Have you removed the repository also? When global update is enabled (settings tab), after every pull an automatic replication to alle repositories starts. This is logged in the task logs. This could explain your ghost replication task.
Global updating is set to yes but I had removed the repository quite some time ago. I did a reboot on the server last night and it looks like the issue went away. I have the pull set to every 6 hours and no replication attempts since the reboot.
Now I just need to figure out why it's not pulling anything. I think I'll delete the job and create a new one.
'Global updating automates replication to your distributed repositories and updating managed systems. Replication and update tasks are not required. Checking contents into your master repository initiates a global update.'
So if I understand this correctly, as long as global updating is checked it will automatically try to do a replication task if the pull job checks in something new.
This would explain why earlier today, when nothing was pulled I didn't get an error and when I just did the manual pull which got updates I got the same replication error.