Thread:Project:Support desk/Opening interwiki-links in a new window doesn't work

MediaWiki 1.17.0; PHP 5.2.10 (apache); MySQL 5.1.41-log.

I've followed instruction here and it didn't work. I move to an non-existing page named e.g. http://en.wikipedia.org/wiki/Apple%22_target%3D%22_blank. What's wrong?