Well, my SEO friend didn’t come through, but I have found an easy way to ensure that Googlebot indexes pages in all languages.
As a pre-requisite, I am assuming that your site is registered and configured with with Google Webmaster tools
I installed and configured the “Google XML Sitemaps” plug-in and generated a sitemap. Note that you can’t add language parameters to the sitemap URLs as Google will flag the entries as errors.
Configure Webmaster tools to automatically pull in your sitemap, and then wait a few days for Google to start indexing your site. You should resolve any errors. After Google indicates that a few pages have been indexed, open up the “URL Parameters” option under “Configuration”.
The message will indicate that no parameter issues are being experienced, but choose “Add Parameter” anyway. A list of parameter keywords should be displayed, and one of them should be “lang”. It will be set to “Let Googlebot decide” as to how to crawl the parameter, but select “Edit” anyway.
In the popup window, change the parameters so that it looks like this.
After the configuration change, Google will try to index all pages with all of the language parameters configured for your site. The Googlebot may have been scanning all languages, but this way, you guarantee that all pages are scanned in all languages. Give it a few more days, then check to see if search results return in all supported languages.
Hope this helps!
