SEO Sitemap plugin - What does hacked mean?

Hi

I am trying to find further info on how All in one SEO has been hacked for wpmu.

When I right click view source my pages, there does not seem to be META data for the Title, content, keywords.

I am no SEO guru but is this a concern?

Is it possible to automatically fill the All in One SEO fields of Title, excerpt and keywords and reflect that in the documents META tags?

Cheers

John