if your talking about the Nextar then the plastic thumb bolts are not tight enough, hand tighten them, then a 1-2 extra with some pliers does it, not so much that the fuse gets dammage just enough so the elevator is not sliding around, just using your fingers won't tighten it enough,after a few flights the plastic bolts need to be snugged up they become loose with the vibration of the engine and should be checked periodicly.
if you try hard enough the stab will move, don't force it to move, but if it's snug and not sliding back and forth and when you move the elevator with the radio then its fine.