I saw this in the manual comments on http://www.mysql.com/doc/R/e/Replication_Options.html:

================ : Note that if you client does not do a "USE dbname", binlog-do-db=dbname will
not binlog a query like: "update in dbname.foobar set foo=1" You explicitly have
to do a USE before a query in order to have your query binlogged, it looks like. Replication on the slave side can do
wildcard matches .. but the master cannot (a la binlog-wild-do-table=dbname.%).
So make sure your clients do a use, if you plan to replicate those tables it updates. ================

Is this still true in the latest version of MySQL? Is this behaviour by design?

Cheers,

Ollie