I am having trouble with my sitemap.xml when I change my blog. I can create an initial sitemap successfully by creating an empty sitemap.xml file and sitemap.xml.gz file and manually rebuilding the sitemap - the plugin creates the sitemap and everything works fine. However, when I edit my blog, I get this error "There was a problem writing your sitemap file. Make sure the file exists and is writable" and I notice that the two sitemap.xml files are no longer in my blog. I have assigned both of them CHMOD 777.
Not sure what to do.