The Lost writers/producers said there are "no paradoxes" within Lost time travel.
They're a bunch of filthy liars, because the Wikipedia article on the Predestination paradox describes Lost time travel exactly.
http://en.wikipedia.org/wiki/Predestination_paradox
2/3/2010 Update:
And now, they acknowledge there are paradoxes in an EW interview:
"The idea of continuing to do paradoxical storytelling is not what we’re interested in this year."
Flip-floppers.