There is another way to get more current. I just wired my own molex to usb adapter. So far, after a couple of hours of testing, it's not having any issues.
Cut a USB extension cable and use the female end with a molex connector. It's pretty simple: red to red, black to black, and it's 5 volts. A little soldering, plus a couple of shrink tubes and it's done neatly. There are pictures out there
such as these on this subject.
So basically my system is this:
Launch HD5870
bios: 012.019.000.006.036339
Cat 10.7
Bizlink dp to dvi
firmware .34
powered by molex to usb
working so far.
Edit:
Don't know what happened, but my system started having issues with displayport link problems, and the displayport monitor no longer was detected properly. So just to be on the safe side, I wired up a 2x usb male to 1 female connector. Now it's ok again.