MobilePre , noise during playback+recording

[grottescofresco]

Hello everyone

I have a major problem with my mobilepre mk2 . Whenever I record any instrument (including voice) there is this annoying high frequency noise on every note I'm playing . The link below has a sample recorded in order to hear it in first place . As you can hear the noise isn't static.

http://picosong.com/LF73/

I don't know how to get rid of it .

I tried every usb-port with no result . I tried powering the sound-card with a self-powered usb hub ( as recommended in many forums ) ... Again nothing...

I have updated all the things I should , like audio interface , Pro Tools ..
I have optimized my windows for audio-oriented projects.
All cables are balanced quality cables..

The funny thing is that the noise may sometimes ( 2 out of ten times ) be less annoying , WITHOUT CHANGING ANYTHING ON HARDWARE OR SOFTWARE!!

But most of the times the problem exists ( 8 out of 10 !!)

I have plugged all my devices in a single wall power outlet to avoid ground loops ...(as recommended in some forums )

The only devices that are connected to my usb-ports are my mobilepre mk2 , the mouse cable and the iLok for pro tools.

I can't find out what's wrong .. Please HEEELPPP!!!

[Craig F]

I'm not hearing any electrical or data noises but I'm not on good speakers right now

[grottescofresco]

crank it up a little and you'll hear it !!!

[grottescofresco]

It's been some time since the last time I recorded with my MK II . It still has this annoying noise .

PLEASE HELP!!!