Comment 1 for bug 246381

I had the same problem. To solve it, I narrowed the search to the function random_sleep...... It sleeps....... 30 min????

# sleep for a random intervall of time (default 30min)
# (some code taken from cron-apt, thanks)
random_sleep()
{
    RandomSleep=1800
    eval $(apt-config shell RandomSleep APT::Periodic::RandomSleep)
    if [ $RandomSleep -eq 0 ]; then
 return
    fi
    if [ -z "$RANDOM" ] ; then
        # A fix for shells that do not have this bash feature.
 RANDOM=$(dd if=/dev/urandom count=1 2> /dev/null | cksum | cut -c"1-5")
    fi
    TIME=$(($RANDOM % $RandomSleep))
    sleep $TIME
}

Very odd, I just commented it at apt, line 222, and It's working again.