It's not really a question of eliminate an option. The navigation bar was added with ACT! 2000 (version 5) and there was an option to change to the navigation style used with ACT! 3-4. When ACT! was rewritten for ACT! 2005 (version 7) the method and programming for the layouts was completely different from ACT! 3-6 and the older style of navigation from ACT! 3-4 was not included.