Error web part is not registered as safe

Jul 1, 2009 at 7:56 AM

 Hi all, i've installed the package TST.BlackBelt_20090122.zip, after the installation 2 webparts working well (ContentByType and ListItemFilter) but the other 2 (PageColumnFIlter and WebContexFilter) when I try to use i received this error :" The Web part or Web form control on this Web part page cannot be displayed or imported because it is not registered on this site as safe". I received the same error when i go in root site settings - WebParts and click on the webpart for preview.

In google i've found this article : http://support.microsoft.com/kb/835590/en-us

My Wss 3.0 is in italian language.

Thanks for help

Alessandro