I've flushed four work units today, including one that was completed less than an hour ago, and they're not on the list yet, so I think there is probably a set update schedule. In fact, if you look at the
User History (this is the SETI Cavalry, I'm still doing WUs for the PowerPot), you see that there are no results listed for the 15th or the 16th yet. Either that, or I'm just "

".