I found the culprit, but language switching still does not work. The installer creates incorrect settings when host site access is chosen during installation. In each language site access, the site.ini.append.php contains a SiteURL setting that is incorrect, for example "eng.1/folder/where/ezP/is/installed/index.php" for English.
Commenting this out leads to a working URL after clicking on a language link, but no language switch occurs. I have read several forum posts dealing with host SA and multilanguage, but so far I could not find any that would give detailed enough and working directions, so I am really open to suggestions...
