I've solved several problems, written several symphonies, and even had a blinding epiphany or two about how to solve all the world's problems that I've managed to drag up into the waking world. All were either complete nonsense or useless. (e.g., the solution to my graph theory problem is not to force feed my homework to a goat and then look for the answer in the pattern of the resulting droppings). I think it's news when someone finds a good solution in their dream precisely because it doesn't happen often.

Sleeping on the problem and having fresh insights of course is such a common experience as to be pedestrian.