That's again neither a fix, nor the root of the issue, but only a trigger!
Ok, now it's clear what you meant

Btw it's a weird one. After fixed one time it remain fixed (differrently from the Ferrari Challenge TP issue…). I even made a hdd (new sata III barracuda, 2,5" 1tb) for a friend and I checked the GT4 stutter, it was present. Solved it, then I sent the HDD to my friend, and stutter has not returned.
