This should be easy to reproduce, just enter flycam mode (left button on the space navigator) while on a vehicle that is moving to another region, e.g. a boat. Observe, as the vehicle (and thus the avatar) crosses regions, the flycam jumps by 256m, presumably because the origin switches to the new region but the offset stays the same.
What should happen is that the camera stays in the same location (modulo potential rounding errors), presumably someone just needs to add/subtract 256m from the relevant axis of the camera position on crossing depending on the direction of the crossing in the spot where the origin is moved to the new region.