I've been having the same problem lately if I follow the WorldPerks Award reservations prompts, but if I go in like I'm going to buy a revenue ticket it usually goes through. I also switch between the (800) 225-2525 and the (800) 447-4747 numbers and often if I don't get through on one I will on the other.
That said, it's ridiculous that Elite members should have to go through this nonsense just to speak to an agent!