What's the Problem after Wordpress update ???

Hi,
i updated my Wordpress-Installation to 2.8.6 and now it's not working with WPG2 (3.0.7) and following is displayed: What's the problem ?

Security Violation

The action you attempted is not permitted.

Back to the Gallery
Error Detail -
Error (ERROR_PERMISSION_DENIED)

* in modules/core/classes/GalleryView.class at line 168 (GalleryCoreApi::error)
* in main.php at line 318 (GalleryView::loadView)
* in main.php at line 94
* in modules/core/classes/GalleryEmbed.class at line 179
* in /wordpress/wp-content/plugins/wpg2/wpg2template.inc at line 76 (GalleryEmbed::handleRequest)
* in ??? at line 0
* in /wordpress/wp-includes/plugin.php at line 339
* in /wordpress/wp-includes/template-loader.php at line 7
* in /wordpress/wp-blog-header.php at line 16
* in /wordpress/index.php at line 17

System Information
Gallery version 2.2.5
PHP version 5.2.11 cgi
Webserver Apache/1.3.34 Ben-SSL/1.55
Database mysqli 4.0.27-standard
Toolkits SquareThumb, ImageMagick, Thumbnail, NetPBM, Gd
Operating system Linux infong 2.4 #1 SMP Thu May 28 16:09:02 UTC 2009 i686 GNU/Linux
Browser Mozilla/5.0 (Windows; U; Windows NT 6.0; de; rv:1.9.1.3) Gecko/20090824 Firefox/3.5.3 (.NET CLR 3.5.30729)