Need help with strange head unit problem?

[Clio_Sport]

Bought a new head unit last week (Alpine IDA X001 I-pod head unit) It is awesome and is the best unit Ive had by a million miles. But theres just one niggly problem. When I turn the volume up, when it gets to a certain volume, it turns itself off, and then turns itself back on a starts turning itself up on its own, then when it gets to that volume again, it turns itself off, and keeps doing this

I thought it was a problem with the head unit, but then I tried fitting it in my mates car and it works absolutely fine and I could turn it up to whatever volume I wanted

So Im guessing its a problem with the wiring in my car?

Any ideas???????????????

 

[Dj Rpm]

Is it speed related?

Stock Renault units have a speed input, that make it raise it's volume when going over certain speeds.