The only reason I can think of (and hopefully someone else will come along that knows more than I do)is Buy it Now listings..I rarely use BIN but when I did I had no item specifics either..had to revise on ebay after posting. Sorry, not much help, just something off the top of my head....
Even if I had a saved auction (WITH specifics) and changed it to a BIN, all the item specifics disappeared and I had to revise.