We installed your version of AIO SEO and now we have this message:
All in One SEO Pack
You have version 1.4.7 installed. Update to 126.96.36.199.
Compatibility with WordPress 3.0: 71% (5 "works" votes out of 7 total)
Shall we upgrade it or not?
Also there seems to exist two Simple Sitemaps but only one allows activation. Neverthless, no sitemap.xml is created in the site.