Sound like a line in your httpd.cong file needs changing (Ask your ISP to do this🙂
This is what the relevant section of my (Apache web-server) .conf file looks like - it shouldn't bee too different (Although don't quote me on that!)
AddType allows you to tweak mime.types without actually editing it, or to
make certain files to be certain types.
#
For example, the PHP 3.x module (not part of the Apache distribution - see
#
#AddType application/x-httpd-php3 .php3
#AddType application/x-httpd-php3-source .phps
#
And for PHP 4.x, use:
#
#AddType application/x-httpd-php .php
#AddType application/x-httpd-php-source .phps
//These lines are what's important, they
//need to be uncommented (Lose the '#'
//before them)
#AddType application/x-httpd-php .php
#AddType application/x-httpd-php-
Good luck!
Russ