Hi,
I followed all the install instructions and installed the directory for the XML Sitemap generator in my public_html directory. I created empty files named ror.xml and sitemap.xml and confirmed that the generator admin pages loaded on the front-end. I made sure to set the permissions listed for the various folders and directory. I then tried creating a sitemap by selecting the "Start Creating Sitemap" button, but then the sitemap.xml file disappears from my server (this happened twice, as I double checked to make sure I did it correctly). The generator front-end admin shows the attempted run of the generator and shows 0 pages indexed. I made sure to point to the right location as far as the "save sitemap to" setting goes (inside my public_html directory...unless I should be doing something different there with Codeigniter?)
By the way, my developer asked if anything needs to be done to the .htaccess file to get it to work. Please let me know if yes.