Since I couldn't find an answer in the Adobe forums, I examined my installation.
First, I used the Acrobat Uninstaller and took the plunge.
Then I used the uninstaller in MacKeeper. To be safe, I restarted my MacBookPro.
I opened the diskimage file DesignStandard_CS5_5_LS1.dmg and discovered in the {aylods folder a file called Adobe Acrobat X Installer.pkg. I tried installing from there and it seemed to work OK. That is, I could open a single-page PDF from the Finder, and print it. Then Acrobat would quit. The "Find Updates" command in the Help menu returned an error message.
So I opened (without uninstalling the program) the Install application, and to my delight, found a way to select Acrobat Pro to install, without the other applications. Further, my authorization number was automagically filled in!
Within 2-3 minutes I had a functioning Acrobat Pro 10.0.0 - it opened multipage document, I could turn the page, search, etc. I did "Check for Updates" and found 10.1.10 available. It downloaded quickly, installed correctly.
I can now call this issue resolved. I just wish it had been easy to find instructions about how to reinstall Acrobat Pro from the downloaded disk image file. Yay! Got my application back.