I was having this same issue. I figured out it was an issue with my theme. I had this as my index.php:
<?php get_header(); ?>
<?php get_sidebar(); ?>
<div id="main">
<div class="main">
<?php global $query_string;
query_posts($query_string . "&showposts=-1&orderby=date&order=ASC");
if (have_posts()) : while (have_posts()) : the_post();
if (is_single());
the_content('',strip_teaser,'');
endwhile; else:
endif;
wp_reset_query();
?>
</div>
</div>
</div>
<div id="sidebar">
</div>
<?php get_footer(); ?>
I guess the query is causing the static page to break? I was using that query to reverse the order of my posts (I have an art website and want old at the the top, newest at the bottom).
When I switch back to this, the static page works correctly:
<?php get_header(); ?>
<?php get_sidebar(); ?>
<div id="main">
<?php if (have_posts()) : while (have_posts()) : the_post(); ?>
<?php if (is_page()) { ?>
<div class="main">
<?php the_content(''); ?>
</div>
<?php } ?>
<?php if (is_archive()) { ?>
<div class="main">
<?php the_content(''); ?>
</div>
<?php } ?>
<?php if (is_single()) { ?>
<div class="main">
<?php the_content('',strip_teaser,''); ?>
</div>
<?php } ?>
<?php if (is_archive()) { ?>
<?php } ?>
<?php endwhile; else: ?>
<?php endif; ?>
</div>
</div>
<div id="sidebar">
</div>
<!-- Get footer -->
<?php get_footer(); ?>