Yeah, I've had problems with the Typhoon rockets too, not sure what it is but the 20mm still seems more effective. I tend to leave the rockets in the hanger unless I'm going after M16's. Against an M16 they are reall effective... but so is 20mm or .50 cal.
The tank I hit, or tried to, was standing totally still, and come to think of it, the one I missed with 2 1000lb'rs was right next to the Tower at an airfield. He wasn't tucked in, but he was within 3 tank lengths of touching it. The bombs I dropped had him clearly in the crater, both times, and I made several passes just to convince myself that he was still alive. The fact that he drove away after that startled me a lot.
Soda