+# clear old cached values
+if [ "$1" = "configure" ] && dpkg --compare-versions "$2" lt 4.0; then
+ if [ -e /usr/share/debconf/confmodule ]; then
+ . /usr/share/debconf/confmodule
+ db_set carnet-upgrade/debconf-priority ""
+ db_set carnet-upgrade/check-services ""
+ fi
+fi
+