PTC  Does the full version actually have sound? in the demo version - downloaded three times in case there were problems - all I get is clicking noises (MacBook Pro, 10.6.2) Too bad, since apart from the sound it looks like an interesting game. I also cannot find anywhere to send this sort of 'support' question. All links I can find go back to macgamestore which seems to just be a marketing front.  
(Version 1.5.14)

PTC  Yes, the Release Notes (under Help) for the latest version of QuickSilver on my PPC machine (b53, build 3814) also say

Release Notes: Quicksilver Build 3808

Changes

Fixes a plugin-check bug

So I guess the release notes 'Build' number doesn't get updated!  
(Version 1.0b54)

PTC  Unfortunately I seem to have been right the first time: (copied from their linked web page)

"If you don't currently own TechTool Pro and would like the complete package, click here.

If you do currently own TechTool Pro 4 and want the 4.6.1 update DVD, click here.

If you own an older version of TechTool Pro and would like to upgrade to 4.6.1, click here.

If you own TechTool Deluxe (from AppleCare) and want to upgrade to TechTool Pro 4.6.1, click here."

I don't see an updater as a choice. (I own 2 copies of TTPro.)  
(Version 4.6.1)

PTC  Thank you for the explanation. This was not apparent from their web page. Perhaps when they get their server(s) running properly I can explore further.  
(Version 4.6.1)

PTC  Why is this listed as an 'updater' when the link is to an update page which does not contain an updater but insists I buy Yet-Another-Micromat-DVD? It's irritating to feel there IS an updater but that somehow I am refused access to it.   
(Version 4.6.1)

PTC  Thanks! Trying to mount the un-bz'ed 'dmg' was driving me crazy.  
(Version 10.3.92)