Are you using IDL? If IDL is on, AO nodes shut off by default. You have to check the extra parameter that turns it back on even with IDL.

If you're not using IDL, when you copied my values, where you paying attention to the fact that my units are inches and yours may not be?

Are you using GC? 

How close is the clothing? Is your ray bias (which is set in inches on my screen shots) bigger than the gap? 

Finally - I have seen AO change behavior over recent versions versus the P7 I used in that shoe thread. What version are you using?