I like that iron. I see it for less than $20 online. I may have to order it. What temp do you set it to? I've always just used a cheap RadioShack 15W.

To get your core over 756 you just need to increase your shader clock a little. Just a few steps. It won't by any means limit your max core OC if you turn up the shaders just a bit. I don't know why it does this, but it is an easy work-around.