QuickTime Update in OS X 10.1 not working well

Following up on yesterday's item on problems updating QuickTime in Mac OS X (with "Update or install QuickTime software" enabled), three readers (Tom Ritch, Michael Blake and Richard Dalziel-Sharpe) confirm the following:

1. From the QuickTime System Preference pane, select "Install new 3rd-party QuickTime software."
2. Click Update Now.
3. The window that appears will likely say "No update is necessary."
4. Click the Custom button anyway.
5. There you should see at least one item. It will be listed as QuickTime Update and "Not Installed."
6. Click to enable it and then click the Update Now button.
7. It appears as if nothing gets installed by doing this.

Update: The update did install when Paul Chernoff tried it. We tried it; the On2 and ZyGoVideo updates that appeared installed. But the QuickTime Update one did not.

As noted by Remo Del Bello, the Item Description for QuickTime Update states: "This software adds Sorenson 3 video support to QuickTime (download approx. 0 KB)." The Sorenson addition fits with previous speculation that a lack of this support was a cause of the symptoms. However, the 0KB suggests either that the update does not really exist and/or it is not really needed.

Note: See also this item on the main page for related info.