Lots of causes. Might be something simple, or a combination of things. As an amateur the fixes on your own can exacerbate the problem and turn your game into a mess. You can try fixing on your own with some good instruction books (recommend Leadbetter's Faults and Fixes) or save a lot of time and frustration by finding a good instructor.

Time to make an appointment with the Doctor, your local PGA Professional.

It sounds like all arms and no lower body. I echo Frank. Time to see the doctor.

Choose wisely, some doctors studied harder than others!

Yes, a visit to a pro is probably best...but thats not what you come to a discussion board to hear, am I right? The good news is that the block-push and the snap hook are the result of the same problem: an in-to-out swing usually coupled with the clubhead coming in low under the swing plane. If you are late with your release you leave the face open but square to the swing path and get the block-push and when you try to correct by getting your hands to release quicker it shuts down the clubhead but still traveling on the in to out path producing the snapper.

The fix is much trickier without actually seeing your swing...which is why you always get advice to see a pro. I would bet though that you swing the driver pretty flat and try to feel a bunch of lag. If thats the case try this for a "feel" fix. Set up to the ball, take your normal grip and then take your right hand off the grip. You should feel the butt end of the club pressing up against the heel pad of your left hand. Now start over with both hands on the club but this time swing back about a quarter turn and make sure you include your normal shoulder rotation...now take your right hand off the grip. Your left wrist should be flat but the butt of the club should still feel like it is pressing up into the heel pad of your left hand. Now, with only your left hand on the club keep rotating and raising your arm and hand up to shoulder height. The clubhead and shaft should be moving around your body and definately above and behind your hands as your wrist hinges. Now tell me where you feel the pressure on your left hand? It should still feel pressed up against your heel pad and you can feel that your forearm...specifically your ulna side of the wrist closest to the pinky finger... can press down to raise the clubhead steeper if you wanted. Also, if your wrist is flat, your thumb should be riding on the side of the shaft and definately not supporting the weight of the shaft. Now you can reach up with your right hand and place it lightly into the correct position on the grip. This is how the club should feel in your hands going back AND coming down. This "feel" will keep the clubhead going back on the proper plane as well as keep it from dropping down too shallow and getting stuck behind you. You should never feel that the club is being brought back with the left hand pressing down into the right. At the top you shouldn't want to feel the weight of the club resting on your left thumb. And in the downswing you shouldn't feel the index finger and knuckle pressing down...always the heel pad of the left hand pressing down utilizing the ulna/pinkie/ring finger knuckles. Then maintain that same feeling on the down-swing and hit through the ball as hard as you want and rotate all the way around to the finish.

And if none of that helps...GO SEE YOUR PGA PROFESSIONAL!!! LOL

See a pro. Sounds like a timing issue between your upper and lower body. If you think you are going to push it, you may be over correcting with the wrists and hitting the snap. The other thing to check is ball position.

I love my driver pick your target and swing free don't fear the driver hit it hard at your target and life will be good.

When my driver falls apart I need to slow my swing down to fix everything. and I know a miss a blocky push is caused by my swing being all arms with my hands way too inside.

I'm also having this issue. Either it's smashed up the middle, or a brutal duck hook. I really need a visit with a pro. If I could just get consistent with the big stick, my game would really be moving in the right direction.

I had this problems as well in the past month. So I've got an appointment with our PGA professional and worked on fixing my problems. This will be the best thing to do cause he can analyse your swing problems best

Without someone actually looking at your set up and swing, it would be very difficult to tell you your problem. Seeing a pro is your easiest fix.

Take Dino's advice, and I'll add this much, you're probably not rotating your lower body through impact, standing up a little (early extension), then flipping the hands. Poor timing will equal the block or the flippy duck hook. How do I know that? First hand experience. Go back to your 7-iron, start from scratch.

Had same issue. Went to a Pro and he helped me with my iron game tremendously, but ran out of time for the driver. At least my recovery shots are keeping my scores lower now. Now I need to schedule a driver lesson. Best of luck!