Apple - "cron" processes piling up

Redirect stderr to /dev/null as well as stdout:

* * * * * /usr/bin/defaults delete com.apple.Spotlight userHasMovedWindow &> /dev/null
* * * * * /usr/bin/defaults delete com.apple.Spotlight windowHeight &> /dev/null

From trial and error it seems to be the stderr output of those commands that prevents the cronjob from exiting. I have no clue why that is, but it may be related to permissions to mail the output.