well, the tables get created! v_posts, v_postmeta and v_comments.
all blogs are public, e.g. my sitewide tags plugin works!!
my php_error.log document says this:
[29-Aug-2009 20:33:34] WordPress database error Error on rename of './wpmu/wp_v_posts.frm' to './wpmu/arc/wp_v_posts.frm-0001' (Errcode: 13) for query CREATE OR REPLACE VIEW
wp_v_posts` AS (SELECT '1' AS blog_id, '1' AS site_id, 'wordpress.mu' AS domain, '/' AS path, posts1.* FROM wp_2_posts posts1) UNION (SELECT '2' AS blog_id, '1' AS site_id, 'wordpress.mu' AS domain, '/fussball/' AS path, posts2.* FROM wp_2_posts posts2) made by do_action, call_user_func_array, onesearch_build_views
[29-Aug-2009 20:33:34] WordPress database error Error on rename of './wpmu/wp_v_postmeta.frm' to './wpmu/arc/wp_v_postmeta.frm-0001' (Errcode: 13) for query CREATE OR REPLACE VIEW wp_v_postmeta
AS (SELECT '1' AS blog_id, '1' AS site_id, 'wordpress.mu' AS domain, '/' AS path, postmeta1.* FROM wp_2_postmeta postmeta1) UNION (SELECT '2' AS blog_id, '1' AS site_id, 'wordpress.mu' AS domain, '/fussball/' AS path, postmeta2.* FROM wp_2_postmeta postmeta2) made by do_action, call_user_func_array, onesearch_build_views
[29-Aug-2009 20:33:34] WordPress database error Error on rename of './wpmu/wp_v_comments.frm' to './wpmu/arc/wp_v_comments.frm-0001' (Errcode: 13) for query CREATE OR REPLACE VIEW wp_v_comments
AS (SELECT '1' AS blog_id, '1' AS site_id, 'wordpress.mu' AS domain, '/' AS path, comments1.* FROM wp_2_comments comments1) UNION (SELECT '2' AS blog_id, '1' AS site_id, 'wordpress.mu' AS domain, '/fussball/' AS path, comments2.* FROM wp_2_comments comments2) made by do_action, call_user_func_array, onesearch_build_views`