Here's something new and bizarre. With about 9k energy, from camp, I closed Diggy from the app list and then relaunched it. When it came up I only had 3k energy. 6k disappeared during the short interval that the game wasn't running.
Why has it become so buggy? Compare this summer, when this bug report forum was lucky to see more than one new post on any given day. Clearly there's been a change in the management's approach to things (likely how much money to spend on testing) ... not, though, a change I can do anything about. Not individually. Getting anything done about this unwelcome change will take organizing ...