I just purchased the Gaggia Titanium (replaced Gaggia Symphony) and, when talking to customer service regarding an error message I was receiving about there being no bean in the hopper -- even though it was full -- I was told that the type of coffee beans I use may cause problems. I was told that dark roast beans (some of which are oily) should not be used. But this is an espresso machine and espresso beans tend to be dark roast! Can someone assist me in telling me what types of beans I cannot use with this machine? I had no such problems with the Symphony, so I'm not terribly pleased with this development.