Upvoted initially because this seemed like a good example of what I've taken to calling a "leprechaun" - a fact that spreads in spite of limited empirical backing; however a quick Google search (fact-checking the fact-check, as it were) leads to this article which at the very least suggests that the second-hand story told above is somewhat exaggerated: the evidence for bleeding associated with Gingko Biloba is rather more solid than "one case report - of a single person". Upvote retracted, I'm afraid...

(ETA: also, the other story at that link makes for... interesting reading for a rationalist.)