Well, Jim was nice enough to help me out with my problem. I upgraded from MC8/9 to MC10, but needed to upgrade to MC11 instead because it had a better resampler. Jim rescinded and refunded my $15 MC10 upgrade, and I was prepared to upgrade to MC11 for $15 instead.
I installed MC11 and went to the purchase page. The 'rescinded' MC10 was still installed as was the 'legal' MC9.1. The MC11 purchase quoted me the full $35. So I uninstalled MC10 and tried again. It still quoted me $35. I tried to uninstall MC9.1, but it said MC10 was installed and MC9 was not. It wouldn't let me uninstall MC10, which wasn't installed, and there was no way to uninstall MC9.1 which was installed. Something rotten going on there.
So I reinstalled MC9.1 over the top of itself, and the computer still said MC10 was installed but not MC9.1. MC9.1 still showed as licensed. I tried purchasing MC11 again. Still $35.
I tried several other things to try to get this to work. I also wasted two more of my renews of my MC8/9 license, and that didn't help. Finally, I tried "Install from Internet", and put in my MC8/9 registration code. It gave me some complaint about the license being old, and did I want to upgrade. I said Yes. Price $35. However, I looked at the URL of the page it had referred me to. The end of the URL showed an 'upgradefrom' field indicating the Registration Code that was being upgraded from, and it was NOT my MC8/9 registration code. Instead, it was the MC10 license registration that had been rescinded. So, I pasted the real MC8/9 registration code in there where the wrong code was, and Voila, I finally got the $15 registration.
Bottom line: something is wrong. I shouldn't have to paste in the registration code. Most people probably won't have to deal with this because they aren't dealing with rescinded codes, but it is a heads up for anyone who goes through anything similar. If the price being quoted to you isn't what you expect, check the 'upgradefrom' field in the URL of the web page that quotes you the upgrade price. If it doesn't match your registration code, then paste your registration code in there to get the proper upgrade pricing.
PS: Glad to have MC11. So far it has run well. And the new resampler definitely sounds better than the one in MC10. However, as others have said, it is a MAJOR CPU hog. I don't know how 'optimized' the code is, but if you're looking for some code to optimize to help performance, that's a good place to start. Don't even think about resampling unless you're running a 2GHZ processor, and then expect it to use 75-95% of your CPU. (assuming 192k resampling and 4 channel output).