Yes. Quite a few times and have gone through 3 carb bolts so far trying to tighten but end up stripping the hex portion. I actually had this problem again recently at a race and stripped another bolt, now have to order more for myself plus replace the one I had to borrow again from a friend at the race. I've informed Ron about this and didn't seem to concerned about it to inform nova, Italy, about the issue. My opinion is that the carb doesn't sit deep enough past the internal o-ring causing it to push it up and out after the engine is running. Ron's cure is to remove the o-ring around the neck of the carb allowing it to settle deeper into the engine. However, if we have to do that to fix the issue, to me that is a design/manufacturer defect of this engine. If something isn't done to correct it, I may end up dropping this engine and go back to running the CMB Evo-101.
Maybe Ron can comment if he's had any conversations with the manufacturer since he's been made aware of this problem and what they plan to do about fixing it.