after so many year at sharepoint , just notice web part also have permission setting.
below is the detail from the forum.
Background: SharePoint V3 on a hosted server. The user is a "site owner" and "site owners" have "full control" over the site. "full control" has all the options that can be selected for security. This is a sub-site to the main SharePoint site and it does not inhearit security from the parent site. I want site owners to have full control over there individual sites, but not have control over other's sites.
Problem: When the user goes to add a web part to the "Home" page of the site via selecting "Site Actions" - "Edit Page" the only web parts that are available to them are the "Lists and Libraries" web parts that consist of "Announcements", "Calendar", "Links", "Shared Documents", "Tasks", and "Team Discussion".
When a Site Collection Administrator does the same thing as above, they see all the web parts listed above as well as "Miscellaneous" web parts consisting of "Content Editor Web Part", "Form Web Part", "Image Web Part", "Page Viewer Web Part", "Relevant Documents", "Site Users", "User Tasks", and "XML Web Part". Is it possible to make these web parts accessible to the owners of sub-sites with out giving them full control over the entire SharePoint site hierarchy?
I believe I figured out a solution. So, if your curious, here is how I fixed it.
Logged into the top level SharePoint site as a site collection administrator.
Select "Site Actions" - "Site Settings"
In the "Galleries" Colum, select "Web Parts"
With the Web Part Gallery open, select the "Settings" menu and select "Gallery Settings"
Now you should be in the Customize Web Part Gallery window. In the "Permissions and Management" column, select "Permissions for this gallery".
In the "Permissions: Web Part Gallery" Select "Actions" - "Edit Permissions"
Select "OK" to the pop up that is displayed warning you that you are about to create unique permissions, and now you can select "New" and add additional users to the Gallery.
This will allow whomever you add to see all the Web Parts available.