Just because a lot of people keep repeating a rumor, doesn't make it true. This is the Bandwagon fallacy (also called the Argumentum ad Populum fallacy). It would be nice to have the facts from official French sources, then we would know one way or the other, and either way it would be no longer a rumor.
Report: Palestinian, 18, killed in clashes with IDF in West Bank (Haaretz)
from the article: Arafat aide calls on Chirac to reveal truth about Arafat's death