Another fine mess you've gotten us into, Jordy... [Is the new meter a reflected type or an incident type?] Assuming it's reflected, (you point it at things), you can eliminate the spot question by checking out something neutral, like a wall or big sheet of paper. [If it's an incident meter, (you point it at the light, usually with a round-ball defuser thingy), let me know and we can try something else.] Since the camera meter was flaky, I'd mistrust it now. Since the handheld is new, I'd mistrust it also. Trust no one! Can you run a quick test to calibrate both against a third? Then use the one that agrees. Course, with your run of luck, all three will be different.