drupal jquery version : 1.8
chrome : 24.0.1312.57
Uncaught Error: Syntax error, unrecognized expression: ul.menu a[href=/admin/content]
After looking at the jquery documentation (http://api.jquery.com/category/selectors/attribute-selectors/) we should surround selectors which contain not valid (http://www.w3.org/TR/CSS21/syndata.html#value-def-identifier) chars
Attribute values in selector expressions must follow the rules for W3C CSS selectors; in general, that means anything other than a valid identifier should be surrounded by quotation marks.
Lots of talk around escaping selectors on forums, it seems that for our needs here, simply quoting the string make jquery able to perform the job