It won't work with nvidia cards.  It's compiled for AMD only.  You'll have to wait for Christian to release the miner using CUDA.

At this point it's just not worth it anymore on Heavy.  Price is dropping, tons of miners are coming online, difficulty is skyrocketing.  By the end of the day it will be no more profitable to mine than any other coin.  It's pretty much there right now.

The money to be made was made when miners were still private or by people playing the ups/downs on the exchanges.  For miners this coin is no better than anything else now.