60 Hz Hum from DVI-D

Does anyone else get a fair amount of 60 Hz hum in the speakers when
you plug the DVI-D monitor into the Beagle Board? My speakers are
quiet until I plug in the DVI-D cable. And then the hum arrives.

I'm using an HDMI-A-Male to DVI-D-Female adapter and plugging a
standard DVI-D Male-to-Male monitor cable in to the adapter.

Ideas? It seems like there may be a grounding problem or the like.


Are both the monitor and BB plugged into the same outlet? A ground
lift on the monitor may help too.

The Monitor is plugged into a surge protector with a grounded plug.
The Beagleboard power supply is ungrounded. But it is plugged into an
extension cord that is plugged into the same surge protector.

Do you think if I shifted to a grounded power supply for the BB that
it would eliminate the hum? I'll try it.

What's a ground lift?

Thanks much.