I've just started to hook the ball every once in a while too. But for me it's great news, that means the ball isn't going right off the tee!
The only place to go now is straight.
I'd also like to say I bought a new driver and I started to hit the ball straight/hook sometimes. It's a Titleist 983K with the Aldilis shaft. Now I'm the first one to say it starts with your swing, not your club, but for some reason this club makes me hit the ball well. I assume it's a complete confidence thing, or it's a sheer coincidence that I have finally learned how to turn the club head at the right time and I happen to have a new club.