Latutude C640 DVD-RW Background Noise

[tjrover]

I have a couple of the Dell C640 laptops which I really like, and I wound up with two DVD-RW drives for them. I bought the drives new, from different vendors, at different times, and they are from different manufacturers. The problem is that both of them have background noise, that bleeds through the speakers when a CD or DVD is playing. The noise seems to be associated with the drive motor, although I can't be certain. Does anyone know if this is common, and what to do about it? Note: I also have DVD and DVD/CD-RW drives for these machines that work perfect (no noise).

Thanks,
Tom