Permalinks and Sitemaps

Hi,

I am having some issues with permalinks ..i just saw my web master tools on 404 pages

i tried to update htaccess but not working ..still those old posts returning 404 errors

and also seen some thing diff today 🙁

http://tollywoodzoom.com/sitemap.xml return error

and

http://www.tollywoodzoom.com/sitemap.xml shows sitemap

why it is displaying like this ?