My 2007 (and most bikes I have been around) allow the rear pulley to wobble. When the bike (and hub bearing) are new, the wobble is very slight. As the miles build up the wobble increases, and the result is that the belt tension can pull the pulley forward, and this takes it out of alignment with the rear wheel and belt. The belt will move to the outside and rub on the outside of the pulley, unless you use the axle adjusters to center the belt again....which results in the rear tire being out of alignment. My 2007 only had about 3,800 miles on it when I first noticed the wobble.
(To test your pulley - sit on the ground on the pulley side of the bike, and place your left hand on the front of the pulley and your right hand on the back side of the pulley, and pull with one hand as you push with the other....then reverse your pushing/pulling hands and see of the pulley wobbles. Don't worry about the rotational movement....that is supposed to happen).
My first attempt at correcting this was the simplest/easiest/cheapest method, and it involves cutting a rubber floor mat to function as a shim.

Stewmills has written up a Tech Article on how to do the rubber floor mat shim - the floor mat is available at Home Depot and Lowe's.....it is a carpet runner. (It appears one of his photos has been hijacked and replaced with an advertisement).
http://suzukisavage.com/cgi-bin/YaBB.pl?num=1446828836/0Youzguys has also had a pulley hub bearing failure.
http://suzukisavage.com/cgi-bin/YaBB.pl?num=1462902794Later on I decided that the rear pulley hub was not machined properly, and the hub should really have an tighter fit where the pulley hub inserts into the rear wheel hub. I machined the pulley hub and installed a brass bushing that was a bit larger OD and more closely matched the ID of the wheel hub.
I first bought a piece of brass tube 2" OD x 1.75" ID from Online Metals.

I then put the pulley hub in my lathe and machined the stub so the brass tube was a tight fit.

I then machined the brass to be a slip fit into the wheel hub recess shown in the first photo.
Now I no longer have any pulley wobble. The outer bearing stays in good condition as the entire load of the belt is not putting an eccentric load on the bearing. The outer bearing spins on the axle with the wheel....the bushing only moves as the rubber cushions allow some radial movement between the pulley hub and the wheel hub.
It has been working great, and I had a feeling that Suzuki should have done that in the first place.....the fit between the pulley hub wheel hub is just too large to fit properly. A couple weeks ago I bought a rear wheel from a 1995 Savage from a forum member, and it included the entire rear wheel assembly including the axles, adjusters, spacers, brake and pulley hub. When I took the wheel apart I first noticed that there was not any wobble of the pulley....and I was amazed to see that the pulley hub fit together just like the one I had made with a bushing. It was obvious the fit was much tighter than my 2007 bike was:

After seeing this I made some measurements:
ID of wheel hub: 1.850"
OD of Brass bushing I made: 1.848" (0.002" clearance)
OD of 1995 Pulley hub: 1.845" (0.005" clearance)
OD of other pulley hubs: 1.805", 1.806", 1.806", 1.807" (0.044" clearance)
So it appears that in 1995 the pulley hub was machined to have a much closer fit than later years had....and the later years allow the pulley to wobble. If your bike has a pulley that wobbles, you might be able to find an older hub to correct the poor fit provided on the later bikes.