Very strange indeed!
I had a similar situation with a friends bike. We were headed to a beautiful area to ride in NH, and it is quite hilly. At any rate, I drive to pick up my friend and see her riding her bike around her the area that she lives in. This is a bike that truly doesn't see much action with her, as she has plenty of other bikes to ride. Anyway, she mentions that her Front Derailleur isn't working and I look at it, and it isn't going to... it is absolutely gone! There was a tremendous amount of play in the derailleur laterally,although everything was tight. So she obvioulsy had to opt to ride another bike....
Anyway, I'm glad that you got the situation resolved, at least once the deraiileur arrives!