Is my logitech g25 defective?

I bought a supposedly never used g25 wheel from ebay for real cheap and just got it yesterday. It comes with an rfactor demo. I got the wheel and demo installed on my laptop and while i was racing, the camera views were alternating at random times, horn was honking at random times, car would shut off. All these things were assigned to buttons on the shifter. So i moved them feom the shifter buttons to the buttons on the wheel. I made the paddle shifter the camera veiw changer and nitro buttons were ignition but it still did this. Its like its randomly pushing buttons. I didnt get a chance to try it with another game yet but i was wondering if anyone else had that problem. Do u think my wheel is broken or do i need to change some settings? Thanks.