We are looking at changing to 2003 Native mode in an effort to enhance our domain security and more importantlychange a number of groups without having to re-create them. MS says it will not affect communication within the domain on our clients, just between servers. We have nothing but 03 servers so we should be OK there, but we have external trusts with two other domains. One is 2003 in mixed mode also and the other is 2000. Will switching cause these trusts to have to be re-created? Will there be a problem recreating the trust with the 200 Domain? Has anyone had any problems with the switch?