I ran into the same problem and fixed it (somewhat dirty) by editing wp-admin/includes/media.php, i changed the line 841 from
$form_action_url = get_option('siteurl') . "/wp-admin/media-upload.php?type=$type&tab=type&post_id=$post_id";
$form_action_url = "/wp-admin/media-upload.php?type=$type&tab=type&post_id=$post_id";
this changes the upload form action-url from an absolute to a relative one, the (stupid) absolute url had http://.. (without s) hardcoded. this then leads to an uploading error when submitting the form, because apache rewrites the request and sends a code 302, which generates another request to the correct url (with s) but, strange, without POST data.
see my fix as "worksforme", there might be a better solution. for example to exclude /wp-admin/media-upload.php from being rewritten by apache (but then the uploads will not be transmitted securely).
edit: this is for wordpress 2.5.1