Umm... There's a setting in System Preferences > Desktop & Screen Saver that will turn off menu bar transparency...Use the Secrets prefpane or Onyx to turn off the transparency for the menubar (even if your Mac does not support transparency). Select either gray or white for the menubar and apply.
It took me about a year before I discovered that and I tried everything. Transparency has to be off on the menubar before the black will apply.