Not so:
If you have trouble migrating 1.4.6 to 1.5.1, use the procedures that used to migrate 1.3.6 to 1.5.1.
If your server is 1.3.6, problems migrating to 1.5.1 may occur.
In this case, place the dbdata files, delete files and clsconfig config, start your server 1.5.1 with 1.3.6 database, stop...