So okay, I tried some other function
window.document.unicycle.SetVariable("_level2/airport/clock/klein:test", "help..!");

have a look at it at http://www1.unicycle.net/mozilla_test.php,
1st with explorer then mozilla... it still just doesn't work!
(click on the movie, press <s>, then <enter> to skip intro).
Can it be Mozilla can't reach into multiple swf's?