i found the problem
am using to code
<?php if( get_post_meta($post->ID, 'ecpt_gallery', true) ) { ?>
<div id="galleryshow"><img src="<?php bloginfo('template_directory'); ?>/images/gallery_large_left.png" width="4" height="35" align="top">
<div><?php echo do_shortcode('[fsg_link class="showgallery"]'.get_post_meta($post->ID, 'ecpt_gallery', true).'[/fsg_link]');?></div>
<img src="<?php bloginfo('template_directory'); ?>/images/gallery_large_right.png" width="6" height="31" align="top"></div>
<?php } ?>
then
<?php the_content(); ?>
so if i uploaded 10 pictures and i insert 2 pictures into Posts ,
2 Pictures will display ONLY in full screen galleria
when i remove this 2 pictures ( from Post content ) , i can see all pictures displayed in full screen gallery