One that happens and not easy to spot is hitting 3 wood from a severe up slope. The ball actually hits the ground just in front of you taking a load of distance off. I've seen a few replays that show this.
But you're right. I've had shots come up woefully short recently. It could just be that I didn't really hit the club I thought I'd selected.
WGT admins have stated that the wind gusts.
Then there's just plain old VEM. About all you can do is mutter WTF to yourself and move on.