/etc/crontab should never be modified. instead use /etc/cron.d to install cron tasks

automated install/basic-install.sh

@@ -255,8 +255,11 @@ curl -o /var/www/html/pihole/index.html https://raw.githubusercontent.com/jacobs
 }
 
 installCron(){
-mv /etc/crontab /etc/crontab.orig
-curl -o /etc/crontab https://raw.githubusercontent.com/jacobsalmela/pi-hole/master/advanced/pihole.cron
+curl -o /etc/cron.d/pihole https://raw.githubusercontent.com/jacobsalmela/pi-hole/master/advanced/pihole.cron
+
+# in most cases, cron should pickup pihole automatically but to avoid
+# any edge cases, the service should be restarted.
+service cron restart
 }
 
 installPihole()

automated install/uninstall.sh

@@ -20,8 +20,23 @@ apt-get -y remove --purge dnsmasq
 apt-get -y remove --purge lighttpd php5-common php5-cgi php5
 rm -rf /var/www/html
 rm /etc/dnsmasq.conf /etc/dnsmasq.conf.orig
-rm /etc/crontab
-mv /etc/crontab.orig /etc/crontab
+
+# attempt to preserve backwards compatibility with older versions
+# to gaurentee no additional changes were made to /etc/crontab after
+# the installation of pihole, /etc/crontab.pihole should be permanently
+# preserved.
+# @TODO: debugging statement alerting user of this.
+if [ -f /etc/crontab.orig ]; then
+	mv /etc/crontab /etc/crontab.pihole
+	mv /etc/crontab.orig /etc/crontab
+	service cron restart
+fi
+
+# attempt to preserve backwards compatibility with older versions
+if [ -f /etc/cron.d/pihole ]; then
+	rm /etc/cron.d/pihole
+fi
+
 rm /etc/dnsmasq.conf
 rm -rf /etc/lighttpd/
 rm /var/log/pihole.log