As sure as I can be. I first downloaded the installer only - just to see that it expects other data files now (and so I downloaded the new data files as well, just to be sure).
When the new installer didn't work, I downloaded it once again, this time using a different mirror (as mirroring issues are still pretty common). But this one doesn't work as well. I even rebooted the PC inbetween to ensure it doesn't keep any files somewhere in any kind of "hidden" cache (Virtual Store in Win7 and/or similar "features").
All to no avail, unfortunately.
Thanks for assuming a wealthy wallet behind the term "loads of expensive hardware", even though this is (unfortunately, again) not the case. Too bad I already bought the "Patch"/"Upgrade" Version and am not willing to pay twice.
Too bad as well that I already contacted customer support a few days ago, asking to exchange the "Patch"/"Upgrade" version with the full one.
Too bad, for the third time, that customer support didn't take notice of my inquiry yet. So I'll stick with the version I bought and paid for.