JavaScript syntax highlighting: failing to highlight comments properly

[offtone]

The online demo behaves as expected, but when I download the source
and run the kitchen sink or demo examples, the comment shown in the
example below is highlighted as a regular expression and not a
comment, simply because it is it the first line of the function. If I
add a line of whitespace above it, the line is recognized as a
comment.

Example (works in the online kitchen sink demo, but not locally when I
download the .tar.gz and run THAT kitchen sink):

function () {
// I am styled with regexp rules because I'm the first line
// I am styled with comment rules, because I'm not the first line
}