Creating a branch is an OK thing to do. However, I'm not sure how much that really helps - CVS does a pretty good job and making appropriate updates, and if the target is really changing, you can just as easily keep a private copy until done (a branch in CVS does not do any merging for you, it just gives you a place to store that file and do within CVS diffs). I think the most likely cause of the problems was MT had a habit of re-arranging the layout of files, so a bunch would get removed and then added someplace else (cvs has not mechanism to rename a file except by doing it on the CVS server directly to the files, and even then, that would require some hackery). You probably know what works best. I have no problem with you doing a branch if you think that will be the easiest thing to do.