Strange Volume Issue

[OHMYX5]

Hi, I installed a DICE unit in my X5 a few months ago and last week, whilst on a long journey, I experienced this weird problem.

Whilst on iPOD via the DICE, when I increased the volume, it would automatically be reduced. No matter if I used the Dial on the SATNAV or the button on the steering, it would reduce itself, like an auto cutoff for volume.

Could it be because I was traveling above 100km/h? When I switched to Radio, it did not do this. Only when I was using the iPOD/DICE.

At first I thought that maybe my iPOD (which is in the boot area with the CD Changer) was rubbing against something and that the volume was being lowered there. But I moved the unit on my trip back to where I know there would be no inteference, and it would behave like this on most of the time as well. I normaly do not have this problem, but on this trip, it was really weird.

Sure hope someone can relate to my problem and offer some 'sound' advice. Thanks.