PHP is supported on the CGI-BIN server only. The 'planet' servers (like ganymede, cirrus, mars, jupiter, etc) do not run PHP scripts. PHP is run in safe mode.
Maybe this will help the problem, because spometimes when i refresh ur php script it tries to download, meaning your server isn't even trying to parse it (means its not supported)... if scorpius is a planet server (which i think it is), or you havn't upgraded to use extra features like cgi etc, then u wont be able to run any scripts PHP / CGI etc at all...