Suzuki XL7 Humming Noise
 

My wifes 04 XL7 2wd ismaking humming noise coming from the rear at anything over 30mph. My first thought was bearings, but there is zero play in the wheels (which I don;t know if that makes any difference on these.) If the differential is going, what kind of noise would it make? Any other ideas? I'm trying to avoid taking it into suzuki unless it is covered under warranty.
Thanks in advance.

Did you ever correct your noise?