I've been having a similar problem on all sorts of city pairs. On about half of my flights, they're ignoring the calls for the elites, although they'll let the elites on anyway. It's almost as if they don't want to publicize the fact to the non-elites.

On my BOS-LHR flight last week, after about five minutes of no F/J pax bothering to pre-board, I asked the "Premium Services Representative" that had barracaded the door if she could let us elites on. She gave me an angry look and said no, and wouldn't call elites for another five minutes.