Otterbox, The modification way.
Alright, So apparently my Otterbox is really dirty when you zoom in this much, but this is a Samsung Infuse 4G Otterbox placed on a T-Mobile Galaxy S2 SGH-T989.
As you will see, the open area where the volume rocker slot is needs to be extended downward otherwise the case will hold the volume rocker in the down position. I could have been a lot cleaner cutting it out, but I was in a rush. It only requires about an 1/8 inch cut out, If you line them up you will easily see the problem.
The case doesn't full snap to the right of the charger port, it comes very close but has caused no problems and once the outside rubber/silicone skin is on, makes zero functional or aesthetic difference.
The back speaker hole is corrected but just slightly offset, I didn't notice any difference at all, as it is so minimal.
If you'd like any additional pictures or have any questions please let me know.