Not a bad attempt but Yah, maybe you can try reducing the exposure. I've seen some nice shots by other Clubsnappers b4. Maybe can get tips from them.
I think 1 big prob is the sky (and water) is almost completely dark while the lights and fireworks are bright. The exposure difference is too great. But this is something we can't control. Had they fired the fireworks much earlier, the colours will be much more dramatic.
Incidentally, not sure if it's right, but I notice chromatic aberration in the images. But this is inherent in most if not all compact or prosumer digicams under such lighting conditions. You probably will probably get 'cleaner' images if u use a DSLR.