Rear Bearings

I've had the rear wheel bearings on both sides changed twice within the last 4 months on my 1997 VW Trek (Jetta), and am hearing the noise again. Looks like It's off to the mechanic once more. :rolleyes:

Anyone have any experience with this problem? I called a few WV dealers and was told it's a common problem and they're not sure what causes it.

i have only replaced rear wb 2 times and both because the aftermarket shop doing rear brakes didnt tighten the axle nut down properly.