Steve,
It sounds to me like you are casting overhead and that causes the hooklength to turn-over the top of the float.
While an overhead cast is fine (if feathered) for a waggler, i.e. bottom fixed only, it is the kiss of death to a stick float.
To cast a stick float, efficiently, take the rod in your 'rod hand' and take hold of the last dropper shot with your other hand.
Next take the rod across your body still holding the last dropper shot and slightly flext the rod tip by excerting pressure with the hand that is holding the last dropper shot.
Now, in a smooth, single movement, cast the float with a sideways action and just before the float hits the water, you describe a letter "C" with the rod tip.
This will ensure that you lay the float, hooklength and bait in a straight line just slightly downstream of your position.
Next, mend the line so that you have the rod tip in direct contact with the line to the float.
This is another one of those things that is so easy to demonstrate and yet so difficult to describe in words. That said, I am sure that there are some FM members local to you who would be only too pleased to give a practical demonstration.
Good luck with one of the most satisfying methods of float fishing ever invented.