Anyway, I remember seeing the episode of LOST which this mystery refers to, and I remember hearing exactly what it says in the quote below (from the LOST article on Wikipedia), but I was later dissuaded from this belief by others. They were wrong!
When Boone tried to send a Mayday radio message in "Deus Ex Machina", he identified himself as a survivor of Oceanic Flight 815. The response Boone received was garbled, and led to a debate for some time as to whether it said "We're the survivors of Flight 815" or "There were no survivors of Flight 815." In a recent interview with TV Guide (May 29, 2005), Damon Lindelof solved this mystery, stating that the response was in fact "We’re the survivors of Oceanic Flight 815." However, Lindelof also reminded readers that this was also what Boone radioed over, saying "it's up to extrapolation as to whether or not his own words were being bounced back to him."
This certainly adds another layer!
Oh yes, and one more thing. I recently bought the LOST first season DVD. Interestingly, if you freeze-frame just before the polar bear leaps at Sawyer, a strange figure appears, somewhat like a Chinese or Japanese character, but not exactly. I doubt it's a mistake!!! But what is it?