unLoadMovie used in screen presentation

I am trying to unload a movie that I loaded in a previous screen of my presentation. The 2 screens are on the same hierachical level.

The first screen successfully loads move from actions layer in its timeline: loadMovieNum("_dev_logo.swf", 1);

The second screen seems to ignore: unloadMovie("_dev_logo.swf");
The movie continues to play into the second screen ie after user has clicked onto next screen.

Any ideas what Im missing here?

RGds

Malco