[Plugin: Multiple Post Thumbnails]More than 3 thumbnails per post?

Hi, Really weird. With this plug-in activated I can’t get it to display more than 3 post thumbnails.

add_theme_support( 'post-thumbnails' );
set_post_thumbnail_size( 588, 392, true );

$thumb2 = new MultiPostThumbnails(array(
'label' => 'Secondary Image',
'id' => 'image2',
'post_type' => 'page'
)
);
add_image_size('post-image2-thumbnail', 190, 190, true);

$thumb3 = new MultiPostThumbnails(array(
'label' => 'Tertiary Image',
'id' => 'image3',
'post_type' => 'page'
)
);
add_image_size('post-image3-thumbnail', 190, 190, true);

$thumb4 = new MultiPostThumbnails(array(
'label' => 'Fourth Image',
'id' => 'image4',
'post_type' => 'page'
)
);
add_image_size('post-image4-thumbnail', 190, 190, true);

The above code gets me the ability to upload 3 thumbnails: the Featured Image, Secondary Image and Fourth Image.

However,

add_theme_support( 'post-thumbnails' );
set_post_thumbnail_size( 588, 392, true );

$thumb2 = new MultiPostThumbnails(array(
'label' => 'Secondary Image',
'id' => 'image2',
'post_type' => 'page'
)
);
add_image_size('post-image2-thumbnail', 190, 190, true);

$thumb3 = new MultiPostThumbnails(array(
'label' => 'Tertiary Image',
'id' => 'image3',
'post_type' => 'page'
)
);
add_image_size('post-image3-thumbnail', 190, 190, true);

The above code displays all 3 thumbnails correctly : Featured image, Secondard Image and Tertiary image.