Mysql table join fails

Hi everyone, I've got a problem joining tables across databases using PHP 4.0.0 and Mysql 3.23.16. I have 2 setups - 1 at home and one at work. The query is fine at home where I am running PHP 4.0.1, but at work (PHP 4.0.0) the page is blank when I would expect to see data returned. I can't believe this is a bug in 4.0.0, and just wondered if there are any config parameters which would prevent me joining tables across databases? Has anyone had this experience? Thanks in advance. Arnie. Query is : SELECT mp3.id, mp3.filename, mp3.title, mp3.album, g.genre AS genre, m.mood AS mood, t.tempo AS tempo, mp3.file_length, mp3.year, mp3.comments, mp3.song_length, mp3.media_type, mp3.banned_for, mp3.on_hold, a.name AS artist, mg.name AS master_copyright, pg.name AS publishing_copyright FROM musicstate.track AS mp3, track_info.genres AS g, track_info.moods AS m, track_info.tempo AS t, musicstate.artist AS a, musicstate.master_groups AS mg, musicstate.publisher_groups AS pg WHERE mp3.genre_id = g.id AND mp3.mood_id = m.id AND mp3.tempo_id = t.id AND mp3.artist_id = a.id AND mp3.master_group_no = mg.group_no AND mp3.publisher_group_no = pg.group_no AND contract_id = $id