OK. 3rd proper flight, first in ideal flying conditions - negligible wind, not a cloud in the sky but at first I thought I'd forgotten to take the gimbal lock off as I get a warning gimbal overheating yet I hadn't. Only other thing I could think of was the filter so checked that was properly and fully on and it was, so the only other thing I could think of was the weight of the filter though it eventually came good. Is this common? Thanks.