User with Editor role, cannot save options

I’ve developed custom plug-in for displaying advertisements, one of the settings pages inside custom admin menu is using the settings_fields API, to save options. Problem is because admin user can save them, but editor can’t.

Questions:
1. Is this API meant only for admins?
2. How to change that, hacking the options API?
3. Is there some sort clash with ADminize plugin which I also use?

Thanks!

Here is the code:

<form method="post" action="options.php">
    <?php settings_fields( 'obvestilo-nast-g' ); ?>
    <table class="form-table">

        <tr valign="top">
        <th scope="row">Naslov obvestila</th>
        <td><input type="text" name="naslov" value="<?php echo get_option('naslov'); ?>" /></td>
        </tr>

        <tr valign="top">
        <th scope="row">Besedilo obvestila</th>
        <td><textarea name="besedilo" rows="8" cols="40"><?php echo get_option('besedilo'); ?></textarea></td>
        </tr>

    </table>

    <p class="submit">
    <input type="submit" class="button-primary" value="<?php _e('Save Changes') ?>" />
    </p>

</form>