Axe Fx Ultra and PC Noise

Hi everyone
I have and an Axe FX Ultra going into a tascam dm4800 desk which connects to my pc  running Sonar 8.5 producer via firewire.
My problem is when using medium to high gain settings i seem to be picking up the pc reading or writing to the hard drive.
I havent noticed this before and i dont think it is the ultra. I have tried plugging the pc, desk and ultra into different plug points but that doesnt make any difference. I havent got any lights on in the room (hard to see but im willing just to get rid of the noise haha)
Just wondered if anyone else had come across this problem before.
The pc monitor is a 28" hanns G LCD and the weird thing with this is if i turn the monitor off you still get the noise. but when you turn it back on again the noise goes for a couple of seconds and then returns. Weird?

Thanks for any input.

Si

Hi Jim
No i usually use the 1/4" but i did try an xlr cable and you could still hear it.

Cheers
Si

The axe fx has a ground lift built in and it still makes the noise with it enabled. I am now wondering if it could be the firewire connector on my pc. Someone on the axe site suggested either swapping pci slots or using another firewire interface. Its worth a go

Thanks Jim

Si