Problem with G2Bridge, JFusion and Gallery2

I've installed Gallery 2 for the 8th time (4 times i've installed the full package and 4 times the typical package).
Last time, after billion of problems i've been able to login correctly, upload my albums and configure gallery2.
Then i've enabled the g2bridge on joomla and all work fine, finally i've enabled JFusion (always in Joomla) to enable the dual login and to import in gallery2 all the users that i've in my site.

I've enabled the JFusion and then:
1) I can't login on my gallery2 script (i don't receive any error but when i press the button to login, the page reload in the main page of the gallery and nothing happens)
2) The random image panel created by JFusion on my Joomla reports:
"Fatal G2 error
Here's the error from G2:
Error (ERROR_BAD_PARAMETER)

* in modules/core/classes/GalleryEmbed.class at line 1001 (GalleryCoreApi::error)
* in modules/core/classes/GalleryEmbed.class at line 852 (GalleryEmbed::getBlock)
* in /web/htdocs/www.reggianasupporters.it/home/administrator/components/com_jfusion/plugins/gallery2/forum.php at line 123 (GalleryEmbed::getImageBlock)
* in /web/htdocs/www.reggianasupporters.it/home/administrator/components/com_jfusion/plugins/gallery2/forum.php at line 43 (JFusionForum_gallery2::renderImageBlock)
* in /web/htdocs/www.reggianasupporters.it/home/modules/mod_jfusion_activity/helper.php at line 256 (JFusionForum_gallery2::renderActivityModule)
* in /web/htdocs/www.reggianasupporters.it/home/modules/mod_jfusion_activity/mod_jfusion_activity.php at line 88 (modjfusionActivityHelper::renderPluginMode)
* in /web/htdocs/www.reggianasupporters.it/home/libraries/joomla/application/module/helper.php at line 173
* in /web/htdocs/www.reggianasupporters.it/home/libraries/joomla/document/html/renderer/module.php at line 84 (JModuleHelper::renderModule)
* in /web/htdocs/www.reggianasupporters.it/home/libraries/joomla/document/html/renderer/modules.php at line 41 (JDocumentRendererModule::render)
* in /web/htdocs/www.reggianasupporters.it/home/libraries/joomla/document/html/html.php at line 190 (JDocumentRendererModules::render)
* in /web/htdocs/www.reggianasupporters.it/home/libraries/joomla/document/html/html.php at line 386 (JDocumentHTML::getBuffer)
* in /web/htdocs/www.reggianasupporters.it/home/libraries/joomla/document/html/html.php at line 249 (JDocumentHTML::_parseTemplate)
* in /web/htdocs/www.reggianasupporters.it/home/includes/application.php at line 168 (JDocumentHTML::render)
* in /web/htdocs/www.reggianasupporters.it/home/index.php at line 79 (JSite::render)"

I hope this is only a mistake in the JFusion's cookie, but the Login Checker in it says that all is ok with the authentication in gallery 2!

This is my plugin conf in JFusion:
Full URL to Software= http://www.reggianasupporters.it/galleria/
Full Path to Software= /web/htdocs/www.reggianasupporters.it/home/galleria/
Cookie Domain= .reggianasupporters.it
Cookie Path= /

Now i've disabled the JFusion's Gallery 2 Plugin, but i still can't login. It's unbelievable!

Please, help me!

Gallery version (not just "2"): 2.3.1
PHP version (e.g. 5.1.6): 5.0.4
PHPInfo Link (see FAQ):
Webserver (e.g. Apache 1.3.33): 2.2
Database (e.g. MySql 5.0.32): 5.0
Activated toolkits (e.g. NetPbm, GD):
Operating system (e.g. Linux): Windows XP
Browser (e.g. Firefox 2.0): Firefox 3.6