I found a little bug in xowiki-portlet. I created a wiki page and included an swf file. in xowiki directly the flash animation is shown but when I add the page as a portlet to dotlrn only the text is shown but not the flash film.
passing header-properties from the xowiki include to the dotlrn master templates was not implemented.... and is quite tricky. i never figured out, what a clean way is to pass properties form includes to the master, esp. when the includes are deeply nested.