silly car charging problem

[diceman]

i picked up a cigarette plug that has a usb port on the back and am using the stock usb cable straight into my mogul to charge while driving. problem is, the phone doesnt charge. before you go on about what the charger is rated for, it is 5v @ 1000mA, which is equal to the stock charger that plugs into the wall.

the phone senses that it is plugged in, the battery just doesnt charge. is there any type of charging "cycle" that it needs to go through to make sure the battery doesnt overheat because when i picked up the phone after about 25 minutes of driving it was fairly warm on the back and i have not noticed that when it is plugged into a computer or into the wall.