PowerColor HD6870 - 3rd monitor not working

[dextercry]

Hi! I would like to connect a 3rd monitor to my PowerColor HD6870 but only 2 monitors work.
Right now I have 1 monitor connected with DVI and 1 with HDMI
The 3rd monitor I want to connect it with ether DVI or mini displayport

for mini displayport I have this adaptor

Here is my org.chameleon.Boot.plist

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>EthernetBuiltIn</key>
<string>Yes</string>
<key>GraphicsEnabler</key>
<string>Yes</string>
<key>AtiConfig</key>
<string>Duckweed</string>
<key>AtiPorts</key>
<string>5</string>
<key>IGPEnabler</key>
<string>Yes</string>
<key>Kernel</key>
<string>mach_kernel</string>
<key>Kernel Flags</key>
<string></string>
<key>Legacy Logo</key>
<string>Yes</string>
<key>Timeout</key>
<string>2</string>
<key>GenerateCStates</key>
<string>Yes</string>
<key>GeneratePStates</key>
<string>Yes</string>
<key>UseKernelCache</key>
<string>Yes</string>
</dict>
</plist>

And about this mac:




I mention that the minidisplay works if I unplug the DVI monitor

 

[dextercry]

No1 can help me ?