Installing MU plugins AFTER Multi-DB is installed

I have multi-db installed and working with 16 db's. Now that it's in place, I'm noticing many of the mu-plugins I'm installing are getting their db tables placed in wpmu_d rather than in the wpmu_global database.

Is this normal? Does this mean for each new mu-plugin I have to:

(1) manually move all the tables (like wp_blog_activity, wp_comment_activity, or wp_forums) to the global db ??
(2) add a new "add_global_table" entry to db-config.php ?

I thought that once multi-db was installed, new mu-plugins would install their tables to the global db automatically. Am I wrong?