The Health Check after our V11Domino upgrade helped us spot this..

We've just completed the deployment of Domino 11.0.1 

There was just one thing we needed to do. The upgrade had put Updall in the ServerTasksAt2 line and we didn't want that as DBMT is used on this server (integrated with Defrag.NSF+), luckily the post upgrade Defrag.NSF+ Health Check pointed this out and offered a one-click removal.

Give it a try http://preemptive.com.au/defrag

This also acts as a timely reminder that adding the notes.ini setting SetupLeaveServerTasks=1 prevents your server task lines from being changed during future setups.