"It appears now that I might just not have been waiting long enough, because when I tried it again this morning, and paid careful attention to what it was doing so that I didn't give up too soon, the LiveCD did eventually come up, and the rest of the installation went very smoothly.
"Mandriva is the only Linux distribution I have tried so far which recognizes the VIA Chrome9 graphic adapter, and set up X Windows to use the openchrome driver. Adam pointed out that the version distributed with Mandriva 2009.0 was still unstable, and gave me a link to a more stable version. I downloaded and installed that, and the display works absolutely flawlessly! For the first time, it picked up the 1280x768 resolution without a lot of struggling with the xorg.conf file, and it starts and runs smoothly and quickly, as evidenced by the messages in the Xorg.0.log file. It is truly wonderful - Adam, thank you very much!"
