Why would in_category only return one post in a specific category?

it should be

in_category(7)

integer, not string.

but a better way to do this is:

query_posts('cat=7');
if ( have_posts() ) : while ( have_posts() ) : the_post();

endwhile;
endif;

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)