Blank page whentrying to load an image

Hello to all;
I am having problem when I try to upload an image to Gallery.
If I try to create a new album I do not have any problem, but as soon as I try to load an image to it, I receive a blank page.
Here are the details of my configuration.

Gallery version = 2.2.4 noyau 1.2.0.6
PHP version = 5.2.4 apache2handler
Serveur Web = Apache/2.2.8 (Mandriva Linux/PREFORK-5mdv2008.0)
Base de données = mysqlt 5.0.45, lock.system=flock
Boîtes à outils = ArchiveUpload, Dcraw, Exif, Getid3, LinkItemToolkit, Thumbnail, Gd
Accélération = none, none
Système d'exploitation = Linux Linux.smcb14.org 2.6.22.19-desktop-2mdv #1 SMP Mon May 5 20:55:05 EDT 2008 i686
Thème par défaut = matrix
gettext = activé
Langage = fr_FR
Navigateur Web = Mozilla/5.0 (Windows; U; Windows NT 5.1; fr; rv:1.9.1.7) Gecko/20091221 Firefox/3.5.7 (.NET CLR 3.5.30729)
Lignes dans la table GalleryAccessMap = 10
Lignes dans la table GalleryAccessSubscriberMap = 230
Lignes dans la table GalleryUser = 9
Lignes dans la table GalleryItem = 228
Lignes dans la table GalleryAlbumItem = 61
Lignes dans la table GalleryCacheMap = 0

For your information I am running Gallery embeded in a joomla installation
Here is the Joomla info : Version Joomla!: Joomla! 1.0.15 Stable [ Daytime ] 22 February 2008 23:00 UTC

The problem is the same, even if I run Gallery on its own.
So pleaase, could you help me.
Best resgards.