unexpected problem with php-5.3

[Bernard <bdebreil@teaser.fr>]

Hi to Everyone,

I just finished installing Apache, mysql and php on a new laptop on 
Squeeze. The server works fine (http://localhost sends a "it works" 
message), MySQL also works fine, as I have been able to copy a database 
from my Desktop under Lenny. PHP 5.3.3-7 ('with suhosin v0.9.32.1') has 
been installed.

Problem is:

http://localhost/MyDirectory/index.php => doesn't work !  The system 
proposes that I download the file 'index.php' !  *.html files are 
treated, but not *.php. The same system does operate allright on my 
Desktop under Lenny (not the same versions of php an mysql though)

Am I missing something ?