I had a similar noise problem in a receiver, and it turned out to be a bad IC in the receiver. It also only occurred in a particular set of surround modes, not all of them and not in stereo.

While your description seems to pin the problem down, there are still some variables to weed out so you can locate the problem.

I don't know your particular receiver, so some of this may not apply, but --

Does this noise come through both surround speakers? Always?
Check the surround mode that your receiver is in when you switch to DVD, and check this mode with other inputs as well. Also check to see if the noise occurs when you have the inputs switched to analog, or to DTS, or whatever...