Bicycle Mechanics - How do I mount this rear derailleur?

I'm trying to replace my rear derailleur. I've never swapped one before so this is all new to me.
I'm stuck at the stage on how to mount my new RD onto the hanger. The interfaces are slightly different.

I tried to mount the new RD, but I realized it appears to use different mounting interface (where it connects to the hanger). After 10 minutes of trying various angles to mount it, it seemed like none of them was looking correct. There seems to be a cutout on the back of the mounting flange, so I tried to align it to the hanger edges, but it overlaps each time and doesn't look right.


So I figured I'd post here for help. I checked my bike mechanic book, searched BF, googled but I'm still not sure how to proceed.

Thanks for any tips

First pic shows my old RD
2nd pic is comparison of old (top) and new (bottom)
3rd pic is rear mounting "flange" of new derailleur
4th pic is my attempt to mount the new RD, but it's not aligning smoothly. The little metal flange doesn't seem to line up with the contours of the hanger

fwiw, here's a link (http://bike.shimano.com/catalog/cycle/products/component.jsp?PRODUCT%3C%3Eprd_id=845524441771275&FOLDER%3C%3Efolder_id=2534374302039973&ASSORTMENT%3C%3East_id=1408474395181419&bmUID=1141926292081) to the new RD I'm trying to install

Hmm...I played around with it some more, and *think* I may have mounted it correctly?
Can someone take a look at my pics and comment if I've fastened my RD using the correct orientation/placement?

See that small 'spring tension' screw? (not the hi/lo adjustments, but the one that adjusts the spring rate I think) Do I have that thing pointed in the right location/direction? Or is it supposed to be further underneath the derailleur hanger. ie should the RD be rotated more CCW?

Thanks

Pics didn't upload for some reason. Here they are:

Ahh, found my answer on the web

"Put the new derailleur into position, holding it up and back (clockwise) from its usual position, so the tension adjusting screw is above the notch on the hanger."
http://www.utahmountainbiking.com/fix/rderailr.htm

So, I *believe* my mounting position is correct then. If someone knowledgeable here can confirm, that would be great. Thanks

That looks right to me. The little screw in your picture is to adjust the body angle of the RD.

Cool, thanks for the confirmation. I'm off on a ride in 5 minutes!

Looks like you figured it out. Make sure you can shift all the way up and down on the stand before you road test it! :)

Take it to a shop. If you can't figure this out you are going to have some major problems dialing it in.

But heres a hint the top bolt screws directly into der. hanger.

Thanks for the feedback guys. I managed to dial it in so that it's now running perfectly & smoothly, woohoo!
The bike mechanic/repair book I have provided the instructions on how to adjust the hi/lo and barrel/finetuner. And now it's now running silently, and gear changes are crisp and solid.

What a nice evening for a bike ride. I even got to "ding" a couple roller-blading in the bike lane :D

http://sheldonbrown.com/gloss_ba-n.html#btension