Thanks for the tipps! With IE7-mode it actually works.
I also had the problem, that the theme didn't work with IE7, so I switched the SCORM-course to open in a new window and changed the head for the popup.
As one little addition I've added the following condition:
<?php if ($modname == 'scorm') {echo("<meta http-equiv='X-UA-Compatible' content='IE=7' />");}?>
Now it should only use the IE7-mode for SCORM-popups. In the first tests it seems to work fine.
Thanks again!
Christoph