I have read every thing I can find on this subject.
I got the HIS Displayport to single link DVI Eyefinity Adapter and it says on the adapter case ACTIVE.
Windows 7 2-S24B300 1-HP 2511 monitors
Windows will not detect 3rd monitor and AMD Catalyst will not detect it.
Tried all setups 2 dvi+displayport 1 dvi 1hdvi+displayport.
you should connect you monitors in the following way.
Video Card - DVI to DVI of Monitor (S24B300)
Video Card - DVI to DVI of Monitor (S25B300)
Video Card - Display Port to Active Adapter to DVI of Monitor (HP 2511)
as a test you can also test all the monitors individually on each of their connections to check its all working before connecting all 3 at once. its possible you could have a faulty cable, active adatper, port on video card or monitor.
any of those will cause the problem you are seeing.
All the cables are good all 3 monitors are good the adapter works as long as one of the other monitors are not detected.
I read your guide and every thing I could find on google before I made this post. Thanks for your reply.