I know it's not what you want to hear, but I'd send it back to REKAT. Since that's the last thing you want to do with a new knife, try this. Find the tiny allen wrench that fits the little bolt holding the thumbstud. Take a pair of hemostats and wrap the jaws with electrical tape, or pad them with pieces of leather. Hold the thumbstud with the hemo's and use the allen wrench to remove the bolt. Dress the bolt with a tiny bit of Lok-tite, then re-install it. Remember to turn the bolt and not the thumbstud. I've never had this problem myself, but that's how I'd try to fix it.