Hiding or Disabling Menu Items

Another user interface debate came up at work today. Do we hide links when they're not available or do we show them but deactivate the link? A quick google search returned a link to the brilliant Raymond Chen's entry on the matter. Doesn't answer the question but provides some guidelines. I remember reading a Slashdot headline of an interview with an ex-Apple guy who touched on the same question. I couldn't find the link, but I want to say it was with Jef Raskin.