Thanks for sharing try number two. Interesting to see the controls behave better at those settings.
One thought: while I don't have even a fraction of the experience of others here with PV2012, I do find the I get the easiest whites separation by using the tone curve panel.
I think the basic panel controls in PV2012 are doing their darnedest to preserve highlight details and so no matter what you do the effective tone curve of all their fanciness is going to have a shoulder for output tones close to white. Trying to be "film-like" I guess, and usually pretty desirable. However, it seems to prevent strong white separation.
I've found that if I want strong separation of output whites the best method is to move to the tone curve panel (which will let you clip easily and doesn't try to protect you from yourself) and move the end control point to the point that clips what (if anything I want clipped) and then add a steeper curve to the white end of things with another control point.
I think restricting yourself to the basic panel you may be fighting a loosing battle. You are trying to separate whites - increase the contrast up there - but I think those tools are specifically designed to try and prevent that. Better to leave your "whites" a bit grey but well separated with the basic panel and then drag the tone curve to shift them to the white output levels.
There is probably a big risk that I'm really just kludging things by doing this and missing some other technique because of lack of experience, but so far that's the best method I've found for strong white separation. If I'm all wet hopefully someone will jump in with a correction.
EDIT: I see I cross posted with Jeff, and he mentions using the tone curve as well. Hurray, apparently I figured something out halfway useful on my own!