1. it shouldn't be spamd -d .. because this way you're calling the daemon binary itself, and will not fork into the background, it'll stay in the foreground until you kill it (with f.e. CTRL-C).
2. The cron entry is something that you've added manually, the dist-upgrade will not change manually changed values/settings etc. You've added that entry, so it's you're responsibility to see if it still works.