I18N characters displayed incorrectly in Excel view with Weblogic 8.1

I18N characters are not displayed correctly in excel view running on Weblogic 8.1. The chracters are replaced with 'question marks'.

JIRA standalone (Tomcat 4) produces an excel view with these characters displayed correctly - so the encoding is correctly set.

Weblogic incorrectly handles the encoding as set on the page for content of type 'application/vnd.ms-excel'.

The attached files indicate the issue - issue 'TP-999' contains Chinese characters that are displayed/encoded correctly when viewed as 'text/html'. The excel files are not encoded correctly showing these characters as question marks.