If it doesn't die when the brakes are applied at a standstill, then it's probably not the brakes fault it is dying. Sounds like it has something to do with the motion of stopping that kills it. Does it start back up fine after it dies? Try throwing the transmission into neutral before stopping and see if it still does it. If it doesn't, then something in the tranny, maybe a clutch, isn't disengaging and causes the engine to stall. If it still does it then, It would make me think it's something fuel related. Have you changed the fuel filter lately? It's fuel injected right?