4th bearing in 3 years, thats not too-too bad. I just put 2 in within the last 6 months, took it in to get the clutch replaced (don't have time, otherwise would have done myself) and they said the bearing is bad again. I dunno if I'm getting scammed by the dealer or not but: I have a hydraulic press (I NEVER beat on it w a hammer), I always torque everything to spec, triple check the Axle nut torque, and I generally know what I am doing.
FLASH75: When pressing the bearing into the knuckle you have to put pressure on the outer edges (I usually just place a my 1/4" x 2" steel "pressing" bar across the face of the bearing). When pressing the hub into the Knuckle/bearing assembly, you must press (or support, depending on which side is up in the press) ONLY on the inner race.
When the hub is being pressed on, it is being pressed into the inside of the inner race. Therefore if you only support the outer race (knuckle in this case) what happens is that you end up pushing out the 2nd half of the inner race out the back of the bearing. At that point you've also messed up the alignment of the ABS ring (if ABS equipped) and re-installing it as-is will probably result in ABS/Tone Ring gap being out of spec (2 mm i believe) and surely cause an ABS light and possibly cause your ABS to kick on when coming to a stop with the wheels slightly turned.