From what I can remember, there are a few things to keep in mind.
Hot water is more willing to give off it's heat due to vapor pressure of the increased temperature. Every time you see water giving off 'steam/vapor' it is in effect cooling istself to reach an equlibrium. (with the room temp)
2nd, hot water has less dissolved gas than cold water. You can easlily illustrate this point by taking 2 20oz bottles of diet coke. Place one of them in the very back bottom of your fridge. Place the other on on top, outside the fridge. After 24 hours gather the warm and cold bottles and open them. You will notice a LOUD pffffffft comming from the warm bottle, and you will notice barely any from the one that was in the fridge. The colder the water the more readily it can hold dissolved gasses. The warm bottle of pop can't hold as much dissolved gas, at room temp or higher it is super saturated, though it can hold it in suspension due to the pressure inside the sealed bottle. As soon as you open the bottle you are equalizing the pressure between the liquids surface and the surrounding atmosphere.
So, as I digress...
...disolved gas in a water impeded the 'hydrogren-bonding' involved with the freezing process. You can do another simple experiment to see the difference. If you were to take a cup of water and boil it in the microwave and take a cup of water directly out of the tap and freeze them both, you will notice that the one that came from the tap will be cloudy. Whereas the cup of water that you boiled will be almost crystal-clear. The couldiness is the dissolved gasses that impeaded in the hydrogen bonding as the water molecules crystalized during the freezing process. (The clear ice is stronger, the cloudy ice will have a tendency to cleave if stressed)
So overall, the hotter water will freeze faster than the cold water due to both the rapid energy lost due to the decreased vapor pressure as well as the lack of dissolved gasses.
-SF