Trying to use table-prefixing but getting error

Hi,

I'm trying to setup a multi-domain configuration of Drupal.

I first tried to share all the tables but cache, then I'll add variables if it works.

I made the appropriate changes to the database (duplicating cache table and pre-fixing it).

The problem is that I get an error:
Call to undefined function: block_list()

Here's how I assignes the $db_prefix variable in the settings.php file:

$db_prefix = array(
'default' => 'ms_',
'access' => 'shared_',
'accesslog' => 'shared_',
'aggregator_category' => 'shared_',
'aggregator_category_feed' => 'shared_',
'aggregator_category_item' => 'shared_',
'aggregator_item' => 'shared_',
'authmap' => 'shared_',
'book' => 'shared_',
'boxes' => 'shared_',
'cache' => 'shared_',
'client' => 'shared_',
'client_system' => 'shared_',
'comments' => 'shared_',
'contact' => 'shared_',
'file_revisions' => 'shared_',
'files' => 'shared_',
'filter_formats' => 'shared_',
'filters' => 'shared_',
'flatforum' => 'shared_',
'flood' => 'shared_',
'forum' => 'shared_',
'history' => 'shared_',
'locales_meta' => 'shared_',
'menu' => 'shared_',
'node' => 'shared_',
'node_access' => 'shared_',
'node_comment_statistics' => 'shared_',
'node_counter' => 'shared_',
'node_revisions' => 'shared_',
'permission' => 'shared_',
'poll' => 'shared_',
'poll_choices' => 'shared_',
'poll_votes' => 'shared_',
'profile_fields' => 'shared_',
'profile_values' => 'shared_',
'role' => 'shared_',
'search_dataset' => 'shared_',
'search_index' => 'shared_',
'search_total' => 'shared_',
'sequences' => 'shared_',
'sessions' => 'shared_',
'spam_custom' => 'shared_',
'spam_log' => 'shared_',
'spam_reported' => 'shared_',
'spam_tokens' => 'shared_',
'spam_tracker' => 'shared_',
'term_access' => 'shared_',
'term_access_defaults' => 'shared_',
'term_data' => 'shared_',
'term_hierarchy' => 'shared_',
'term_node' => 'shared_',
'term_relation' => 'shared_',
'term_synonym' => 'shared_',
'textlinkads' => 'shared_',
'tinymce_role' => 'shared_',
'tinymce_settings' => 'shared_',
'url_alias' => 'shared_',
'users' => 'shared_',
'users_roles' => 'shared_',
'variable' => 'shared_',
'vocabulary' => 'shared_',
'vocabulary_node_types' => 'shared_',
'watchdog' => 'shared_',
'wp2drupal' => 'shared_'
);

As you see I just share cache, it's the only table to have the "ms" prefix instead of the "shared_prefix".

If I change the "cache" item's value with "shared_", then it works but it shares all the tables, it's not what I want to do.

Anyone had a similar issue? Any ideas on how to solve it? Am I doing anything wrong?

Thanks.