I have been reviewing one of my sites stats in google's webmaster tools.. . The site is in 2 diff parts.. one half is in wordpress and the other have is a message board (using SMF- Simple Machines Forum).. in the sitemaps section of g's webmaster tools.. for the forum.. it shows Submited= 2,947 and for Indexed it shows "1"... I have over 37,000 posts on the forum.. The Forum sitemap settings "Maximum number of topics to display in XML sitemap"is set to 40,000..
any ideas why googles webmaster tool is only indexing just 1 but alot (most) of the threads are showing up in google.. could it be a reporting error on googles end??
Check your url in sitemap, it can be not match with url indexed by google ( www or non www ).
I also faced this kind of problem in previous. Sometime it is possible in online sitemap creation. People can any sitemap generation software. I am using "Gsitecrawler" for my website.