Try plugging one of the Samsung's into integrated graphics if you have it (Intel system pretty much). You wouldn't be able to game from that screen, but it could work for an extended desktop (that's what I am doing right now, two displays on my GPU and one from the integrated).
Usually Active Displayport adapters are more expensive (~$50) and require a separate power source from a USB cable. I suspect that adapter is actually passive, despite how it says "Active" and "ATI Eyefinity Certified". Also I can see its not a Dual-Link DVI connection on the other end, while to take full advantage of a Displayport you would need a Dual Link cable.
Though looking through the rest of the adapters available, im not so sure on this.
Also it seems someone else has had the same issue as you on another Sapphire card.http://forums.whirlpool.net.au/archive/1663202