Can't setup triple monitors with AMD PowerCololr HD7870 Graphics card

[InBeforeHD]

I have just acquired my 3rd monitor, and since my graphics card has 2 DVI and 1 HDMI and 2 Mini DIsplay Ports, I am currently using both DVI spots and using a DVI to Active mini Displayport converter for my 3rd monitor. When i plug in the monitor theres is no signal and when I go to AMD catalyst control centre it says the monitor is 'unkown'. Also a message pops up everytime I plug in the mini display port saying "system has detected a system link failure and cannot set the requested resolution and refresh rate on on your displayport" Note: I am using the same monitor for the triple monitor display. DUal monitors have worked just fine but now problems are occurring with the 3rd one.
Help will be greatly appreciated, thanks!

 

[DarkSable]

Sounds like the DP adapter isn't working correctly. They tend to have issues.

Consider using HDMI? I know it's not ideal, but...

 

[VincentP]

What resolution are you using for each monitor?
Do you have a link to the adapter you are using?

 

[VincentP]

Sounds like the DP adapter isn't working correctly. They tend to have issues.

Consider using HDMI? I know it's not ideal, but...

AMD cards only support two monitors connected via DVI/HDMI/VGA.
Any additional monitors must be display port, or a display port active adapter.

 

[DarkSable]

AMD cards only support two monitors connected via DVI/HDMI/VGA.
Any additional monitors must be display port, or a display port active adapter.

Oooh, right. I do small form factor, so heat matters a lot, so it's been a while since I've worked with AMD cards.

No chance one of the OP's monitors is displayport, is there?