Although P2P-based DVEs can potentially solve the scalability issues, other important issues such as consistency remain unexplored. In this paper, we address neighborship consistency, which is the ratio between the number of known nodes and the number of actual nodes within a node's area of interest (AOI). We address two factors that affect neighborship consistency for DVEs using Voronoi-based Overlay Network (VON). We propose adaptive AOI buffer and critical node detection to reduce the negative impacts of the two factors. We also perform simulation experiments to demonstrate the effects of the two factors before and after adopting the proposed mechanisms.