Well, if you do get a hum problem when the machine is plugged in, just know it's a cheap quick fix by getting one of those 3 prong to 2 prong adaptors at Radio Shack. I dunno if it will occur through the cardbus or not. Generally, it really shouldn't happen to any soundcard with it's own power source, particularly if the shielding is done right. But, that seems to be somehtng that Dell neglected. Only prob I've had with the Dell.