Only one page indexed

Can anyone tell me why when i click on the indexed pages of my site in
the stats section of google sitemaps only one page is indexed. this is
the index page.

Also when you go to the sitemaps tab there is a heading last
downloaded. What does this mean? I have just uploaded a changed site
map and it says that i last submitted 17mins ago and last downloaded 1
hours ago. What does this maen then?

Cheers for any help