in the core/URI.php,ablout line 170：
$_GET = array();
override the original $_GET,which may contains nginx rewrite appended custom query string,i.g.
rewrite ^.* /index.php?tid=5
then the tid=5 will missed because it didn't appear in the url
why not just modify the $_GET but override it ?
tid=5 would appear in the QUERY_STRING value and be re-inserted into the $_GET array by parse_str(). Even if that wasn't the case at the time when this issue was submitted - it surely is now, especially with PATH_INFO having precedence in AUTO detection.