Not all WebParts appear for all users

Apparantly "Users who are members of custom site groups cannot access Web Parts when they view Web Part galleries in SharePoint Portal Server 2003". This is because the webpart gallery is nothing but a custom list - however it is not set to automatically inherit permissions - so none of the custom site groups can access any of the standard webparts in the web part gallery.

To work around the problem, add the custom site groups to the Web Part gallery. Then, assign permissions to the custom site groups. To do this, follow these steps: 1. Connect to the portal site, and then click Site Settings.
2. Under General Settings on the Site Settings page, click Manage security and additional settings.
3. Under Templates and Web Parts on the Manage security and additional settings page, click Manage Web Part gallery.
4. On the Web Part Gallery page, click Modify settings and columns.
5. The Customize Web Part Gallery page is displayed in your Web browser. The URL in the Address box of the Web browser contains a GUID in brackets. Copy the GUID that appears in the URL, and then paste the GUID into a blank document in Notepad.

The following is an example of a URL:
http://ServerName/_layouts/1033/listedit.aspx?List={AE2A9E4C-BE4C-47C6-8A01-45E119543F7F}
In this example URL, the GUID is AE2A9E4C-BE4C-47C6-8A01-45E119543F7F.
6. In a new Web browser window, type the following URL in the Address box, where GUID is the GUID that you determined earlier in step 5:
http://ServerName/_layouts/1033/ShrOpt.aspx?obj=GUID,doclib
Note Make sure that you replace the GUID that you determined in step 5 with the GUID in the URL. To do this, paste the GUID from the Notepad document into the URL.

The following is an example of a URL that uses the example GUID from step 5:
http://ServerName/_layouts/1033/ShrOpt.aspx?obj=AE2A9E4C-BE4C-47C6-8A01-45E119543F7F,doclib
7. After you type the URL and the GUID in the Address box of your Web browser, press ENTER. The Change Permissions: Web Part Gallery page is displayed in your Web browser.
8. On the Change Permissions: Web Part Gallery page, click Inherit permissions from the parent Web site.
9. Click OK on the message that appears.
10. Assign the View items permission to all site groups except for the Web Designer site group. To do this, follow these steps:a. On the Change Permissions: Web Part Gallery page, click to select the check boxes that are next to the site groups that are displayed on the Change Permissions: Web Part Gallery page. Do not click to select the check box that is next to the Web Designer site group.

Note Make sure that the check box that is next to the Web Designer site group is not selected.
b. Click Edit Permissions of Selected Users.
c. On the Modify Permissions: Web Part Gallery page, click View Items, and then click OK.

11. Assign the View, insert, edit, delete items; change list settings permission to the Web Designer site group. To do this, follow these steps:a. On the Change Permissions: Web Part Gallery page, click to select the check box that is next to the Web Designer site group, and then click Edit Permissions of Selected Users.
b. On the Modify Permissions: Web Part Gallery page, click View, insert, edit, delete items; change list settings, and then click OK.

HTTP Error 401.2 - Unauthorized: Access is denied due to server.

This error occurs when "Integrated Authentication" has not been enabled on the website. This is usually the case with the Default Web Site since that is created when IIS is first installed and SharePoint doesn't update the security settings.