6
well the first indicates that you need to update your System module in "System" -> "Modules"
The second is a deeper problem, one that is, honestly, out of my area of understanding.
I'll outline the problem, and maybe someone more knowledgable in internationalization in PHP can help out:
When the rss feed is rendered, the various text data are encoded to UTF-8 like this:
$tpl->assign('channel_title', xoops_utf8_encode(htmlspecialchars($xoopsConfig['sitename'], ENT_QUOTES)));
There are more lines just like this for each string that needs to be added to the feed.
I think that if your installation of PHP has mbstring support then this should work:
$tpl->assign('channel_title', mb_convert_encoding($xoopsConfig['sitename'], 'iso-8859-7'));