Heh. That’s just a typo in my bug report. (Sorry.) On my blog, it’s a proper shebang, and the issue persists.
For anybody else who has this problem, I found a better workaround. If I put some a code block in an HTML comment, that seems to be enough to get SyntaxHighlighter to wake up and do its job.
<--
[code lang="cpp"]xxx[/code]
-->
As long as that is on the page somewhere, the C++ syntax highligher script gets loaded, and the other code on the page gets highlighted.
Needless to say, it would still be nice to have this bug fixed.