Can not create any gallery on a sub site in a multisite WP

Hi All!
I’m running a multisite installation with NGallery, one of the subsite is dedicated to the photo gallery.
I’ve had a lot of problems configuring it, mut the main one is i’m not able to create any gallery in any of the sub-site unless in the main one.
I’ve already tried to desacrivate al the plugins, deleting nggallery both in WP and in the DB, changing .htacces, but i’m still not able to create and manage albums and gallerys.
Files are crated in blogs.dir/sub-site/ but it seems nggallery read that.
Anyone can solve? I’, really getting crazy!
Some infos abaout my installation:
Sistema operativo : Linux (64 Bit)
Server : Apache/2.4.4 (Unix) mod_fcgid/2.3.7
Utilizzo memoria : 46.09 MByte
Versione MYSQL : 5.5.31-30.3-log
Modalità SQL : Non impostato
Versione PHP : 5.3.26
PHP Safe Mode : Disattivo
PHP Allow URL fopen : Attivo
PHP Limite memoria : 128
PHP Max Dimensione Upload : 25M
PHP Max Dimensione Post : 30M
Limite PCRE Backtracking : 500000
PHP Max Tempo Esecuzione Script : 120s
Supporto EXIF via PHP : Sì ( V1.4 )
Supporto IPTC via PHP : Sì
Supporto XML via PHP : Sì
Libreria grafica

GD Version : bundled (2.1.0 compatible)
FreeType Support : Sì
FreeType Linkage : with freetype
T1Lib Support : Sì
GIF Read Support : Sì
GIF Create Support : Sì
JPEG Support : Sì
PNG Support : Sì
WBMP Support : Sì
XPM Support : Sì
XBM Support : Sì
JIS-mapped Japanese Font Support : Sì

http://wordpress.org/extend/plugins/nextgen-gallery/