The Google Custom Search page is a plain setup which doesn't allow for much configuration; I've started learning some of the ins and outs of Google context and annotation files which might enable us to give users the option of filtering by English site or French site, which would be the perfect solution to the problem of the mixed-up language situation. The annotation stuff is a bit puzzling, but I think we should be able to get it working in the end. Current results suggest that not all of the site has been indexed yet, but we have plenty of time to worry about that as we get nearer to completion.