Rockets dropping onto launch pad

[ebondream]

I'm not sure this is a bug, but recently, whenever I try to launch a rocket, it appears a few inches above the launchpad and proceeds to fall down--meaning that unless it's very short, it'll immediately start leaning and falling over. The weird thing is that I used to launch the exact same rockets without a problem. The only thing I changed recently is upgrade the tracking station to level 2, I doubt that can have anything to do with it...