My xbox stops to ftp,stream,smb share.Very strange problem,no one can't figured out what it is...

Hi
From a month I'm having this strange problem.I say "strange",because I can't figured out my xbox's problem!
Let me explain:

I have a 1.4 "blu case" xbox,xenium ice,Seagate 750 GB and ind Bios/x2 5035...
I used to connet by flashfxp,stream movies from my pc,transfer files without any problem until now.

BAD NEWS:
-My flashfxp doesn't connect
-By smb it says "Workgroup not found"
-Adding local network says "error 1073741772"
-No ftp by xboxs
-No ftp by pc
-No ping to my ip 192.168.0.3

GOOD NEWS:
-If I swap my hard disk in another xbox,IT CONNECTS!!!
-The leds of the ethernet port of my xbox light green and orange as normal

So,is not hard disk or pc related,because as I said if i put my hard disk in another modded xbox,it connects to my pc without any problems!
And my xbox NIC is not broken because the leds light and i can see on my xbmc dash the static ip instead of "no link".

MY QUESTION IS AT THIS POINT:

What the hell is the problem????