archive.php page title: “Nothing found for …”

I modified my archive.php to make it suit to my needs. I fetch posts via

$posts = query_posts($query_string . '&showposts=100000');

and walk through the posts with

if ( have_posts() ) { while ( have_posts() ) : the_post();

Strangely, when I call the archive for the year 2008 the title bar of the page says “Nothing found for Schsch 2008” even though there are lots of posts found and displayed.

‘Schsch’ is the root folder of my wordpress blog. My permalink structure leavec the “archive” part out, I call the archive for 2008 with “domain.tld/schsch/2008”

How come this error is displayed? Is there a better way to fetch the posts than with the method mentioned above?

Thanks!