Hello everyone,
After wrote unsuccesfully to Gigabyte support, I'm trying writing here hoping to found someone who had my same problem and who fixed the issue succesfully.

recently I received an used GA P35-DS4 rev2.0 as gift and I've built a PC with the following components:

Mainboard: GA P35 DS4 (bios F14, the latest one released)
cpu: Intel Q6700
ram: 4x2GB samsung PC2 6400 (M378T5663QZ3)
dvd rw: ASUS DRW-24D5MT (sata)
HDD: Kingston SSDNOW sv300s37a120g (AHCI mode)
GPU: nvidia geforce GT610
O.S.: Windows 7 Professional x64 sp1

Once installed and activated the OS everything seemed to run alright. But few days ago I left the PC turned on while talking at the telephone and 10/15 minutes after it was gone in suspend mode.
When I came back for working with the PC I pressedthe mouse button and the PC tryed to resume form suspend mode, but unsuccesfully... infact the PC started run in a strange boot-loop: it turned on for about one second (the fans also turned on again, everything seem start running again...) then it shut down automatically, some seconds after it turned on again automatically for about another second then shut down again, some seconds after it turned on again for another second then shut down again....until I disconnect the power cable from the PC.
Once reconnected the power cable and pushed the pc start button, the PC turn on regularly resuming the previous windows session (incredible!!!!).

Really I couldn't understand what's wrong....there's ome driver to install or update?there some setting to change into the BIOS? I don't know.

Gigabyte support haven't been able to tell me what's causing the issue nor how to fix it, but sure I can't believe that that's the right way for resuming a suspended windows session without damaging the mainboard.

during the past days I searched for the fix on the web without find it.

Now I hope to find here someone who know how to fix the problem and who will help me.