Here i sharing best way for sitemap generator. Just hand-code it - it's not hard to do sitemaps.org/protocol.php. It is best tool for create site map generators.
The page below is from Google's help site and lists 3rd party software. I happen to use Gsite Crawler which is donation ware. I thought it was worth a donation. Here some best source: code.google.com/sm_thirdparty.htm.
ASP.NET with the Sitemap Generator, will be dynamically generated XML in the absence of your site map. You simply install our instructions, and the last date was changed, if the default is not.
I used some XML sitemap generator & had no issues with reading urls. I am not a professional, so I cannot give you any advice on this. Desired to say that perhaps you ought to try another tool.