LEAVE the box ticked ON.

When you uncheck, a completely different render procedure is used.
BB told this a while back too. No artifacts in corners or on sharp edges any more but at the cost of extra render time.

Only uncheck it if you have artifacts.
Corners of a room, square angles.
Artifacts in sharp corners.

Unchecking the IC checkbox , starts a different render procedure, and it does take quite bit longer at advanced render settings and material room specials.

Ps; You all know you can delete full body morphs now? :-)

Poser 1, 2, 3, 4, 5, 7, P8 and PPro2010, P9 and PP2012, P10 and PP2014 Game Dev
"Do not drive faster then your angel can fly"!