Well... the reason your browser is trying to download the files is cause apache isnt pasing it correctly. Under you /etc/apache/httpd.conf (or something like that), make sure the following is done:
LoadModule php4_module /usr/lib/apache/1.3/libphp4.so
or the like is uncommented in the file and:
AddType application/x-httpd-php .php
AddType application/x-httpd-php-source .phps
is added to the file. This tells apache to parse any file with the php extension. You could even do this
AddType application/x-httpd-php .maniac
and anything ending in .maniac would be PHP parsed. 🙂.
Hope that Helps!