[eluser]luismartin[/eluser]
I was talking about server cache (CodeIgniter cache which is commonly stored in application/cache). By mentioning the no-cache header I understand you mean browser cache. This would be interesting also, but I want to prevent extra processing from multiple requests from many different users, to which the server cache has been made for.
I've temporarily disabled this cache for the requests coming from ajax, but there must be some way to properly cache (server-side) ajax requests with CI.