Computer & FPS slowdown on region window loadup.

Anyway I'm returning to use isboxer after years of not using and am having severe fps issues on startup. When initiating innerspace the region windows do pop up slowly but the pc grinds "almost" to a halt with each window at less than 1 FPS. It then takes the pc 20+ seconds to register any mouse click or anything else whether inside or outside the game windows. Basically the whole computer becomes so slow its unusable and it then takes me many minutes to close down all the windows so the PC returns to normal speeds (assuming it doesn't stop altogether).
The game is world of warcraft and is a fresh installation. The game functions fine without isboxer. For testing purposes I turned all in game graphic settings way way down including reducing window resolution to 1080. The isboxer is also a fresh install and was set up using the initial wizard.
With my pc spec I should not be having fps issues, at least on the hardware ability side of things so I think it must be something else...
Windows 7 ultimate 64 bit
Intel core i7 3930K clocked at about 4120 Mhz watercooled( I have even tried removing the overclock and yes temps etc are ok)
SLI x 2 Nvidia GTX 780 Ti
16GB Ram
running on single monitor (have even tested on 3 different types as the one I started testing with was gSync and I thought that might be an issues. But no luck on any of them)
I set background fps to 10fps and front to 30 within isboxer. Still no luck.
I tried setting main window to "no slot" etc and fiddled with the various cpu core priority settings.
I have tried various x 5 windows region setups.
Here is the isboxer config from where I last left it after various adjustments (this is not the only config tested): http://www.privatepaste.com/9b249f5fce
I apologize if I have left out any vital info (let me know)
I really appreciate any help as Ive just re subscribed to innerspace and re activated x5 Wow account subscription and don't want the initial approx £60 to go to waste!!
I look forward to your kind help and any time you might spare me.
GR