problem with flv video using excerpt

I’m totally new at php, and trying to create a theme

when listing all articles of a category, or even in archives, I’m using the command “the_excerpt” to only display the first lines of the articles. But if there is only a video in the article (embeded with the plugin flv-embed), the_excerpt bugs and it then display part of the code and no video at all.

Is there a way to display a video, or to only hide it, when using the_excerpt? it of course works fine with the_content