Got exactly the same problem, been out riding no more than 6 times since the beginning of June, and if i do go out, i prefer to sit around on a wall rather than ride. Was even thinking of changing to XC or Road, but just couldn't be bothered to get a bike. Basically i just can't stand riding the same spots in the same order and doing the same stuff on them. What would probably help us is a change of frames or bikes. Can't think of anything else, unless there are any rocks in your area.