I'm having difficulty getting my GBU to release. Generally, I will have everything set up perfectly on first pass, and bomb doesn't release (fall line designator comes down, flashes, pops back up, falls down but goes up again without releasing). Strangely, if I keep the target locked, fly over target, then turn around, it almost always drops on the second pass. Happens EVERY TIME. Any other constraints I need to keep in mind? Usually dropping from 15,000 feet...