i am working to resolve this issue, but this will take a few days.
however, what you are trying to do - left-to-right; top-to-bottom - is in the simplest way done with wrapping the post into a div, fixed width, floated left, right margin; with a counter to add a 'clear-left' to every first post in a row, and a different margin to the last post in a row:
<?php
if (have_posts()) :
$columns = 5; //set the number of columns
$i = 1;
while (have_posts()) : the_post(); ?>
<div class="post<?php if( ($i-1)%$columns == 0 ) { echo ' clearleft'; }; if( $i%$columns == 0 ) { echo ' last'; }; ?>" id="post-<?php the_ID(); ?>">
<!-- core post area; title, content, thumbnails, postmeta, etc -->
</div>
<?php $i++;
endwhile;
next_posts_link('« Older Entries');
previous_posts_link('Newer Entries »');
else:
echo 'no posts';
endif; ?>
the css for this:
.post {
float:left;
width: 100px;
margin-right: 10px;
max-height:150px; /*not necessary*/
}
.post.clearleft { clear:left; }
.post.last { margin-right: 0px; }