[Plugin: Google XML Sitemaps] Dual Sitemaps

I have submitted my sitemap in 2 places

1 – at http://mysite.com
2 – at http://www.mysite.com

Does it make a difference, or am i supposed to delete one of them and its fine ?? my preference is without “www”

Secondly the crawl error coming for deleted pages long time back, is that normal ?

http://wordpress.org/extend/plugins/google-sitemap-generator/