I think mine died at day 24 or 25 and the rest hatched on day 27. Not sure why mine died... I'd like to say it was due to my incubator, but it was under a hen, so who knows?
If you are going to use the still air incubator again, you might want to consider raising your temp to what most people recommend for still airs, which is around 102, I think.
-Kathy