thanks for further testing, even with Uninstall Tool.
You're right: Sometimes Uninstall Tool lists 64-bit applications as 32-bit. The reason for this is unclear. As far as I can overlook it, the concerned apps have been installed in the correct folder. So it's probably more of a bug than a real problem.
The 32-bit program files issue didn't appear during my last, successful attempt. (I didn't mention that point in my "Halleluja! post" ). The same with your installation?
The only remarkable difference between all these aborted installations in the past and the happy last one is, that Windows had been installed several new updates. First I was optimistic that these updates maybe could solve my problem. So I tried again to install after updating and restarting Windows. But the result was the very same...
I know, it sounds crazy in your ears, but the solution has been brought by 12.10 installer -- and nothing else.
One last question:
Can I truly find out within Opus, if the program runs 32- or 64-bit mode? Info dialog reports "64-bit" (see screenshot above).