Thanks for your answer.
I thougt that there is no need to submit the form, neither by the user nor by
HTTrack; the content is displayed without any action.
aside from the form-problem, is it possible to grab these files given in the
parameter list? the problem exists also if I embed the object without the
form-element. HTTrack saves 3DPie.swf, but not the apex_util.flash:

<object classid="...player.swf...">
<param name="movie"
value="/i/flashchart/3DPie.swf?XMLFile=http://mydomain.com/apex/apex_util.flash?p=103:2:1740230002474691:FLOW_FLASH_CHART_R2051203498774178_en-us
</object>