Can't get Eyefinity past 3 monitors

I have been attempting to get this problem resolved off and on for quite some time now. Recently I upgraded 2 of my monitors so that all of them are displayport monitors. I have 4 x NEC EA231WMi and 2 x NEC E231W. They are all connected directly via mini-DP to DP cables (no adapters are used). These are simply single cables running directly from the video card to the monitor.

Yet, I can only get up to 3 monitors to run in Eyefinity. I have been successful in getting Eyefinity to run in 3x1 configs on either the upper or lower rows (I have the monitors setup in a 3x2) array.

I need assistance in getting all 6 screens running in a 3x2 config. I am at such a loss of how to get this to work. Nothing I have tried in the past seems to have worked. I have tried the 10.10 drivers and the most recent 11.6 drivers. No luck! Every time I try to setup a 3x2 setup I see either nothing happen, or the display will change to a different monitor, but with nothing else changed.

Is it possible that the cables are bad? Tell me if these are not correct: I have 3 x 6ft 32AWG DisplayPort to Mini DisplayPort Cable - White (http://www.monoprice.com/products/product.asp?c_id=102&...) and 3 x 10FT 32AWG DisplayPort to Mini DisplayPort Cable (http://www.monoprice.com/products/product.asp?c_id=102&...). Are they too long? Or are the specs just wrong? If so, what do I need?

My system info is as follows:
OS Name Microsoft Windows 7 Professional
Version 6.1.7601 Service Pack 1 Build 7601
Other OS Description Not Available
OS Manufacturer Microsoft Corporation
System Name System
System Manufacturer Gigabyte Technology Co., Ltd.
System Model GA-790XTA-UD4
System Type x64-based PC
Processor AMD Phenom(tm) II X4 965 Processor, 3400 Mhz, 4 Core(s), 4 Logical Processor(s)
BIOS Version/Date Award Software International, Inc. F4a, 7/2/2010
SMBIOS Version 2.4
Windows Directory C:\Windows
System Directory C:\Windows\system32
Boot Device \Device\HarddiskVolume2
Locale United States
Hardware Abstraction Layer Version = "6.1.7601.17514"
User Name Lightning\username
Time Zone Eastern Daylight Time
Installed Physical Memory (RAM) 8.00 GB
Total Physical Memory 8.00 GB
Available Physical Memory 5.37 GB
Total Virtual Memory 16.0 GB
Available Virtual Memory 12.3 GB
Page File Space 8.00 GB
Page File C:\pagefile.sys

Also, the power supply is a Corsair Enthusiast Series TX950 (CMPSU-950TX); the heat sink is a Corsair H70, the operating system is Windows 7 professional 64-bit.