Bike Magazine reported on this problem, many months ago, when they ran the monoposto around their 460 mile test route. There has been no further report on this issue from Bike, although they commented a couple of months ago that Ducati had still not offered any explanation of the fault.
I reckon you deserve an explanation (and a working subframe)!
I have a BP 999S by the way, but I promise I am not smug about it in any way.