TROUBLESHOOTING: Maximus V Extreme + Four 290x Crossfire = NO GO!

Hi guys, so i recently got a couple extra GPUs and some risers (otherwise they don't fit in my system, aftermarket coolers). I'm experiencing nothing but trouble. Please help!

System:
i7-3770k
Maximus V Extreme
2x Sapphire Tri-x 290x
2x VTX3D 290x w/GELID Icy Vision coolers & VRM sink mod
8GB Corsair Dominator GT 2133

Power:
EVGA G2 1300w

2x PCIe 16x 30cm powered risers (for the Icy cooled cards, they take up 2.5 expansion slots)

Here's steps i've taken so far

1. Inserted all GPUs/risers/pcie power/2x molex(for risers). Making sure that the cards are inserted as per the recommended configuration for 4x GPUs according to the ASUS manual (something like 1a,2a,miss a slot,3,4).

2. First boot in win7 - I hear the device inserted noise (the same sound you get from inserting a pen drive or new device). However, i hear it playing about a THOUSAND times within seconds. So much so that it freezes the computer and i have to reboot.

3. I boot back into windows and all seems OK. I run GPU-Z and see that all 4 AMD R9200 devices are listed.

4. Check device manager and i see that two of my display adapters say something like: "Windows has detected a problem with the device and it has been stopped. Code: 43" So obviously something is wrong.

5. Driver re-install.

6. Boot into windows and catalyst control center pops up this time and lets me configure crossfire (allowing me to enable/disable xfire).

7. I navigate to device manager to find that this time one device have the device stopped/code 43 error.

8. Open GPU-Z again and only 3x Radeon R9200 series are detected.

9. Before enabling crossfire, instead i decide to open cgminer (just to see if all detected cards are functioning individually) and BOOM, BSOD system_service_exception.

10. Tried shorter, non-powered 16x - 16x risers. NO BOOT

11. Removed all risers, managed to fit 3 on board (one GPU having the fans totally stuck and not able to move).

WINDOWS BOOTS FINE, EVERYTHING RUNS FINE. Without risers : (

Please does anybody have any ideas?

These are the powered risers i'm using (UK):
https://www.buyahash.co.uk/product/extra-long-30cm16x-slot-powered-riser-pci-e-express-extender-adapter/