CMC of Madness Spells

[Zhalfirin]

Content: What is the converted Mana Cost of a spell played via madness?

Context:  I thought a spell's CMC was ALWAYS the amount printed in the upper right-hand corner of the card (minus morph creatures whose CMC is 0).  Hyperion's post at http://www.themanadrain.com/forums/viewtopic.php?t=40 made it seem that some madness spells have a CMC of zero.  What is actually the case?

[Hyperion]

I was referring to a possible opening hand with multiple Moxen/or LED/Lotus/etc getting hurt by a Chalice at X=0. Sorry about the confusion, I edited it to make that statement clearer.

You are right about the CMC always being the cost in the upper right corner, i.e. the CMC of a Basking Rootwalla is still 1 even if it's cast via its madness cost of 0 (which I'm assuming was the source of the confusion as a result of my imprecise wording).

[Zhalfirin]

I see now whence the confusion came.  Thanks for the response.