When I look at the GEDCOM files that Family Echo generates, I see dates like: 24 APR 1898. This seems to be the standard GEDCOM file format.
I exported my family tree and I see the same results that you're seeing when I changed the dates to MM/DD/YYYY and DD-MM-YYYY just to see if I could get something else to import. So I think you're going to have to convert to DD MMM YYYY for the import to work correctly.