Volume Alternating Problem with DVD Playback

[wxforecaster]

I'm a big fan of the band Rush so I thought my first DVD would be the newly released Rush - Chronicles.

I have a new Dell 8100 and am using WInDVD for the playback.

Video and everything runs just great, except the volume keeps lowers and raising automatically...as if someone were continuously turning the volume knobs down and up and down and up.

Please help...it really renders the system useless.

My specs:
Dell 8100, 1.7 GHz, 256mb SDRAM
32mb DDR Memory Radion Ve Dual Display gphx car
Samsung 16X DVD-ROM (SD-616)
Voyetra Santa Cruz Sound Card
Harmon-Kardon 695 Speakers w/ Subwoofer

Thanks!
-Evan