query_posts(“cat=#”) not working

Okay I’m going crazy here. The following code works great:

<?php	query_posts("tag=sometag");
while(have_posts() && $i <= $posts_wanted) : the_post(); ?>
...
[do stuff]
...
<?php endwhile; ?>

But if I try to do the same loop and specify a category instead of a tag, it returns all posts (not just posts in that category):

<?php	query_posts("cat=3");
while(have_posts() && $i <= $posts_wanted) : the_post(); ?>
...
[do stuff]
...
<?php endwhile; ?>

What is going on here? I’ve tried everything I can think of to get this to work and nothing seems to do the trick!