Upgraded PC causing terrible noise with Digi 002 console

[Fredy]

Hey guys, I need you help.
I have been using digi 002 console for one year now with no problems. I had a laptop PC with i7 processor, SDD, a second HDD for storage using pro tools 8 LE, two powered speakers and everything worked great!. The only problem was that I was running out of CPU power quite often, the i7 was the first generation with 1.8ghz. I am still amazed how well the system was working lately (after overcoming a lot of issues, cant deny that). But because of the processor, i have upgraded my PC to a desktop, using the latest i7 4770k, one SDD and another HDD, FW card digi approved (SIIG with TI chip) and win 7 64-bits. Same speakers and the digi 002 console.
Now the problem is that right when the computer is on and everything is connected (i.e. console to the PC through FW, speakers to console), there is a terrible sound coming out of the speakers. The noise is coming from the speakers with digi 002 turned off! the only thing that stops the noise is when i disconnect the FW cable from the computer. It seems a combination of hiss and buzz but it actually changes when i move the cursor using the mouse. it is a very loud noise (it doesnt stop by turning off the screen display). BTW, everything is connected to the same cable, also i am using a plug that has an isolated ground (same as before with no ground loops).
Lastly, the noise is NOT coming out from the headphones, only from speakers..
I dont know what to do, i would really appreciate your help. Many thanks and peace!