Index: includes/file.inc
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RCS file: /cvs/drupal/drupal/includes/file.inc,v
retrieving revision 1.164
diff -r1.164 file.inc
1314a1315,1320
>   // unset the 'Cache-Control'-header sent in drupal_page_header() to make sure, 
>   // IE5-7 can store the file when transfering files over https connections. 
>   // See http://support.microsoft.com/kb/316431/ for details on this issue.
>   // Additionally, set this file to be cacheable. Modules can still overrule this setting.
>   drupal_set_header('Cache-Control: store, cache, must-revalidate, post-check=0, pre-check=0');
>