Hello,
Eureka is perhaps a good idea, personnally, I begin the problem by the faults in IQLUSION,UNDERGRUUND and DESPARAT-LY. I think at code Caesar.
For French, I think too. Because Vigenere is French.
For the détails of my decoding see my site:
http://groups.google.com/group/kryptos97solution

Chabrery.

RE: Kryptos