If, after installing 10.5.2, you do not have the option to disable the translucent menu in the Desktop & ScreenSaver System Preferences panel, chances are you might have used this previous hint to disable the translucent menu bar.
Taking a hint from that particular hint... reset the value that was set by running this command:
Mac OS X Hints
http://hints.macworld.com/article.php?story=2008021118162850