As above look on the box, might try CPU-z (CPU-id) and see if it says in the voltage reading Vid and if it does that should be your default Vid (assuming EIST etc are turned off). I am just not sure how that program handles i7, with a core 2 if I leave it at defaults CPU-z gives me Vid and labels it as such, if I change it manually in the bios it gives me Vcore and labels it as such.
VID Range 0.6500 — 1.4000
1. Each processor is programmed with a maximum valid voltage identification value (VID), which is set at
manufacturing and cannot be altered. Individual maximum VID values are calibrated during manufacturing
such that two processors at the same frequency may have different settings within the VID range. Note
that this differs from the VID employed by the processor during a power management event (Adaptive
Thermal Monitor, Enhanced Intel SpeedStep Technology, or Low Power States).
set it at 1.35V and see if the stability issue goes away. Thats well within the working range and a bit on the high side but nowhere near the absolute max Vcore. Should not cause any problems etc. etc. and will tell you quick if your suspicion is correct. What to do after that is another question.