We're talking about a Stanley Clarke tune called Working Man that is based on another of his tunes called Lopsy Lu. The Zeppelin reference is to the style of the new version, not to any song that Zep actually recorded. It's not even a particularly heavy version, that's just what the person who wrote the liner notes (Ivan Bodley - never heard of him) came up with.
One weird Zep cover I can think of is Frank Zappa playing the riff from Whole Lotta Love in the guitar solo called Duck Duck Goose from L?ther, the complete version being known as Leather Goods which also has the riff from Dazed and Confused - the reason I bring this all up is because Frank is the one who said, on the classic album Roxy and Elswhere, that Jazz isn't dead, it just smells funny.
(Message edited by hieronymous on April 29, 2008)