Google Confusing Top Level Domains?

domain.com shows domain.de's results

[jonrichd]

A client has domain.com and domain.de. Both are hosted on the same server, and the same content management system is used to administer them.

While the logical content of the sites are the same, the two sites are in different languages, and have different filenames.

When I do a site:domain.com search, several of the domain.de pages show up in the results as URL only pages in the .com domain -- e.g. domain.de/dir/file.htm is displayed as domain.com/dir/file.htm. Doing a search for site:domain.de doesn't show any of the .com pages. As best as I can tell the .de URLS that show up in the .com results don't show up in the .de results.

Making the problem slightly worse is that when trying to access the misidentified pages, the server returns the home page of the .com domain, with a 200 response code, so Googlebot doesn't know that the pages don't exist.

I don't know if there is a solution to this problem, but I know G has been having canonicalization problems, and I wanted to add this case to the mix.