There’s a bug in WP 1.5 where only the Options page for the last-loaded plugin appears:
mosquito.wordpress.org/view.php?id=1196
Fixing it requires a slight modification to menu-header.php in the wp-admin folder. The bug is fixed in the latest WP in the repository though, You can get the latest WP with this command:
svn co http://svn.automattic.com/wordpress/trunk/
Or, you can download this copy of menu-header.php that I got today (rename it, of course):
menu-header.phps
If you use the ContactForm plugin, this will make its Options page ugly, with double menus. To fix that, edit options-contactform.php, deleting the lines at the top starting with “require” and “include”.