What version were you playing, because those issues were supposed to be cleared up. And were you playing on Windows?
Ending 1: Don't gain the golden dragon form and just play the game as normal.
Ending 2: Gain the golden form, but don't have the fight with Quasar and Lionel at the top of Fu-Long's tower.
Ending 3: Gain golden form and have the fight with Quasar and Lionel at the top of Fu-Long's tower.
Ending 4: Go to the small island in the lake area with the purple crystal.
The endings are linear, so if you get ending 3, you can't get ending 2 or 1. And if you get 2, then you cannot get 1.