Corrected entry: There is a scene right before the suns go down where the English businessman states that "anything (referring to his liquor supply) over 45 proof burns quite nicely." This is not true. Nothing under at least 90 proof will flame up like it does in the movie. And even then, only clear liquor will flame at all.
Corrected entry: If the eclipse only comes every 22 years then what do either sorts of monsters eat in-between-times?
Corrected entry: Riddick seals them in the cave and goes to the ship. They fill bottles with the glow worms while he starts preparing the ship. Caroline magically appears outside the cave and climbing over the ridge that is overlooking the "town." She runs to the ship and tells him that she promised "them" she would return with more light. 1. How did she get out? If it was a second hole then the creatures would have gotten in 2. She never said she'd be back with more light to them.