I have activated sitemap wordpress plugin, np for a while but sudenly I got problem. when I posting new article and publish, I got this message Warning: fopen(/home/thetrave/public_html/sitemap.xml) [function.fopen]: failed to open stream: Permission denied in /home/thetrave/public_html/wp-content/plugins/google-sitemap-generator/sitemap-core.php on line 1737 Warning: gzopen(/home/thetrave/public_html/sitemap.xml.gz) [function.gzopen]: failed to open stream: Permission denied in /home/thetrave/public_html/wp-content/plugins/google-sitemap-generator/sitemap-core.php on line 1750 Warning: Cannot modify header information - headers already sent by (output started at /home/thetrave/public_html/wp-content/plugins/google-sitemap-generator/sitemap-core.php:1737) in /home/thetrave/public_html/wp-includes/pluggable.php on line 770 Code (markup): any body know how to solve this problem?