I am part of the moderated YAHOO:Kryptos group so if you have any questions feel free to ask. I will say as far as the DIGETAL misspelling goes, the only thing I have read recently about it is that it was most likely purposefully misspelled if you put stock into the Morse being the source of PALIMPSEST via extracting the letters by looking for palindromes. Spelling digital correctly would have resulted in an unwanted “G”. See Link
http://www.sfu.ca/~nicolea/kryptos/OnTheOriginsOfPalimpsest.htm