It might be over powering it or something. Just use the old one till you get the new graphics card and try again. If it still doesn't work with the new graphics card, come back here and I'll help you some more.
I have already tried it multiple times with the graphics card and with out, i recently tested it on a different computer, worked beautifully. However the other computers set up as far as cord were, was a little different.
So you tried it with the NEW graphics card? Because in your post you mentioned that you're, quote, "getting a better graphics card." So you got the "better graphics card" and you tried it with this new power supply?