One post won’t display when dislpaying posts by tag

Two posts were published on my site on the same day and given the tag ‘Latest Posts’. One of them doesn’t appear when displaying posts by a specific tag on my site. This is occurring in two instances. On the home page where I use query_posts(‘tag=latest-posts&showposts=2’); to call posts with the tag. It is also happening when the ‘Latest Posts’ tag is clicked in the tag cloud. The post has the tag ‘Latest Posts’ and all other posts with the tag ‘Latest Posts’ are appearing. Does anyone know why one of the posts is appearing and one is not appearing?