Steering Wheel Button Intermittently working?

[xr6tjet]

Hey guys,

I put a new sony dvd headunit in my AU and am loving it, got the steering controls hooked up via the aerpro plug and play unit. All works. Just wondering though why only my volume down button seems to work intermittently. Sometimes I press it, does nothing. Another time I'm driving I press it and it works perfect for a duration then later it stops again. I'm thinking it could be the clock spring?

Anybody encountered this problem?

Cheers, Alex.