No, I not tried that and will give it a try when I get a moment.
Thanks for the replies
Corsair has said: We do not recommend mixing separate memory kits as it can cause stability issues. Memory with the same speed, size (GB per stick), timings, and voltage would net your best chance of not having a stability issue. Unfortunately, we cannot guarantee mixing any two kits, even if they have the same part number, for guaranteed stability.
So it seems, there very little chance to get both pairs working with XMP on, due to the different versions.