Hi Guido,
This sort of issue isn't unusual unfortunately - however, just so you know I suspect that your location is affecting the results you're seeing - as when I search Google.com from here in the UK I'm seeing your English content ranking. However, when I search Google.es I'm seeing your Catalan content ranking so either way there are a few issues.
I suspect (although I can't be 100% sure) - that part of the issue is the Catalan vs Spanish content - as they do also speak Catalan in parts of Spain - it may be that Google is struggling to figure out which is the best content to display. There are two things that you can do:
- Set up geo-targeting via webmaster tools (if you haven't already done so) - there's a good guide here: http://www.seo-chicks.com/1463/geotargeting-on-the-same-domain-using-xml-sitemaps.html
NB - you can only do this if you are targeting specific countries - not languages. If for example you want to attract UK and US English visitors then do not implement this.
- Implement hreflang if your content is duplicate (i.e. it's the same content but in different languages):
In terms of implementation you need to place the tag on all versions of the page -
So on http://yourdomain.com/page-whatever you'd need:
So on http://yourdomain.com/page-whatever you'd need:
