If it's the circuit with the kitchen appliances it might, if it's intermittent be worth trying to run one of them off a different circuit (if you've got two circuits for sockets, or say a cooker circuit with a socket) as long as they're on different RCD circuits as well as different breakers not just different breakers protected by the same RCD.
It might also be worth trying them with a plug in RCD between the appliance and the socket if you can, as from memory the RCD in the fuse box may have a slightly higher trip current than a standalone RCD.
It's been a very long time since I looked into it, but at one point portable RCD's often had a lower trip current because you could get a few ma leakage from some devices which added up on a ring circuit, I vaguely remember one of the science teachers at my school pointing out that the lab breakers were something like 30 or 50ma, because otherwise they got nuisance trips on a regular basis, but plug in RCD's tended to be more sensitive (I can't remember the details but remember looking at the ones we'd got at home and finding him right but that was over 20 years ago).