Basically, what skybrian has, in a rather short way, said. As far as I have been able to find out over the years, quantum entanglement "does" operate at speeds greatly exceeding that of the speed of light, but, because of the weird properties of quantum mechanics, no "operation" that could ever be used to transfer data between two sets of particles is possible.
So while they "are" entangled, they are apparently not entangled enough in a stable way such that a change to atom A would be picked up as a new change to atom B (thus, having successfully transferred some sort of information), because the quantum state breaks down somehow.
So while they "are" entangled, they are apparently not entangled enough in a stable way such that a change to atom A would be picked up as a new change to atom B (thus, having successfully transferred some sort of information), because the quantum state breaks down somehow.