OldEd again. I finally sent an e-mail to MasterSketchup describing my plight, and after a few exchange... Why,lo and behold, the download actually WORKED! I believe what happened was that someone rebooted the server. Another friend who is an internet maven - full-time professional maven making Big Bucks - examined my diagnostic results and said that "while it is possible it could be something else, the greatest probability is that the server needed to be rebooted.
ANYWAY it got done, and I downloaded it - the free "Make" version - and I'm now trying to learn it. I do wish that there was a printed tutorial manual. The tutorial is online - a video, narrated by a very pleasant female voice who just speaks a bit too fast, and doesn't leave gaps in her recitation to give the student time to stop the narration and try the actions described.
I love online - the access to everything is great, BUT there is still an important place for paper.