Actually read another person that had a topic sorta like this. (And no, I didn't use a registry hack)
He explained it well:
1: I boot my PC. (DVI plugged into card 1).
2: I start my miner.
3: I switch my DVI cord to card 2.
4: I start my 2nd miner.
and so on till card #4
Anyways, it seems that each card mines it's own share, so I can heat the highest numbers. Also, doing this method allows me to push each card to it's max (as we all know, every card is made slightly different and has different max overclocks..even if they are the exact same card/from the same assembly line). I suppose I like the way I have it setup, makes me feel better about the amount of work I do for the money