Cross posted at http://labs.dagensskiva.com/forum/topic.php?id=152#post-481:
Ok, I've almost completely fixed this problem. Thanks to this blog post:
http://www.code-styling.de/english/how-to-use-wordpress-metaboxes-at-own-plugins
I added some code to the more-fields-object.php file that enables the right sidebar again, and it also saves your open/close toggle states on the boxes:
more-fields-object.php, function init(), at the bottom of the function (before the } ):
add_filter('screen_layout_columns', array(&$this, 'screen_layout_columns'), 10, 2);
then, immediately *after* the final closing brace ( } ) of the init() function:
function screen_layout_columns($columns, $screen) {
$columns[$screen] = 2;
?>
<script type="text/javascript">
//<![CDATA[
jQuery(document).ready( function($) {
// close postboxes that should be closed
$('.if-js-closed').removeClass('if-js-closed').addClass('closed');
// postboxes setup
postboxes.add_postbox_toggles('<?php echo $screen; ?>');
});
//]]>
</script>
<?php
return $columns;
}
This will enable the "Screen Layout - Number of Columns: 1 2 " options under the "Screen Options" pulldown. Probably not the cleanest way, but it's a quick fix.
NOTE: The one thing that does NOT work is if you choose 1 column layout, it moves all the sidebar items over to the main column, then if you switch back to 2 columns, the sidebar items remain in the main column, and you can't drag them back. I'm not sure if this is a bug in 2.8 or what, because it still happens on the normal Edit Post page if I deactivate the More Fields plugin. I haven't tried deactivating all my other plugins.