One of the arguments you can supply to get_posts is posts_per_page. If you don’t include this, then it will default to your Pages Show at Most setting on the Reading page of your settings. http://wordpress.org/support/topic/get_posts-not-pull-all-posts-unless-numberposts-in-query. Yes, I know the forum thread is 2 years old, but it confirms the suspicion that I had after reading http://codex.wordpress.org/Template_Tags/get_posts and the Source File listed at the bottom of that page.
