I suspect we were sent a previously-used, broken machine!
House of Loxley, Amazon
8 December 2012
Summary: When I opened the coffee machine box, I noticed a small amount of water in the machine. It looked unused in every other respect, so I assumed it was simply a machine that had been tested... Big mistake. When I set up and flushed through the machine as directed, from the first cup of espresso made, the coffee "hopper" contained wet sludge which spilt everywhere when the machine was disassembled.
Summary: I was so happy with this machine for about two months, made great espresso. And then... the coffee started coming out really bitter. I tried everything: I descaled, tried brand new coffee, ran water through it again and again. It just kept on being weirdly metallic and bitter. I have read everything about these and still no idea what happened. Delonghi support was rather unhelpful, they had no idea what would cause that if I had descaled it properly (which I did).