Oddly, I had the same chafing issue, and I found (after lots of pain etc) that if I backed off after all that chafing and let myself heal, then went out and did it again, eventually I wouldn't chafe as badly...

but it's a pretty uncomfortable way of doing things. I, too, chafe in that 'where my thighs meet everything else' area... I have an extremely narrow saddle and go commando under my shorts... *shrug*

What's helped for me is a little neosporin post-ride (this is only LONG rides, like 4+ hrs) and wearing boxers or boy underwear about the house.