Oh, no wonder it's confusing. Don't call the cables by
what the plug looks like on the power supply end. They are
not PCI-E power cables, and the cables themselves are not called adaptors. Only the ones with red plugs are PCI-E power cables, the rest are just cables. Call the cables by what they look like on the end that plugs into the device you want to power.
These are the correct names and will save us some confusion and trouble, most of them are correctly scaled to size, ignore the oversize SATA connector, that's just zoomed in to show what each individual pin does.
The two red PCI-E power cables are what you want to have plugged into your graphics card to power it, but as you say, one of them seems to be defective. I don't know how easy it is for you to contact OCZ and get a new cable for warranty purposes, but it is probably easier for you to get an adaptor. There's two types that you can use depending on what connectors you have available. There's
twin molex to 6 pin and
SATA to 6 pin.