It's not likely to be related to a wheel bearing, but if there are issues with the differential, it may be related to the Haldex system.

You will want to get the codes read with VIDA/DiCE so you don't have to guess on where the problem(s)lie-- these are cars with networked electronic modules, and a bad one can affect other systems or even take down part of the network, sometimes in seemingly strange ways until you understand how they interact.