On some servers the global configuration doesnt seem to work. I dont know why otherwise i would have fixed it. So if you have this problem you should set your parameters/options at menu level.
This is how you can do that:
When making or editing a link in the menu manager you will see a box to the right called "Parameters (Component)" this is in Joomla 1.5. In Joomla 1.6, 1.7 and 2.5 you will see a similar box but its called "Add User Frontend".
In this box you will see the component settings for that menuitem only. These settings override the global component settings. This gives you a lot more possibility's using the component. But you can also use these if the global parameters dont work.