In certain circumstances the (parent > child) selector doesn't seem to be functioning correctly.

For example:

$('#footer ul > li').after(' | ');

Firebug reports an error:

"uncaught exception: Syntax error, unrecognized expression: | "

however this is fine:

$('#footer ul li').after(' | ');

but obviously the rule is applied to all child list-items too, which is not the desired result.