Came across a taxing problem installing Joomla component on an old 1.05 installation. The error was:
Warning: copy(/home/example.com/public_html/home/administrator/components/com_rd_rss/rd_rss.xml) [function.copy]: failed to open stream: Permission denied in /home/ucbmedia/public_html/home/administrator/components/com_installer/installer.class.php on line 360
Failed to copy file: /home/example.com/public_html/home/administrator/components/com_installer/component/rd_rss/rd_rss.xml to /home/example.com/public_html/home/administrator/components/com_rd_rss/rd_rss.xml
The problem was caused by ownership. PHP was running in fast-CGI mode as user ‘nobody’. But the user logged into the example.com was ‘example’.
I logged into the server as root and changed ownership of the the target directory (and the source for good measure), and all was well.