When adjusting the cams you may need to change the valve shims to get the proper clearances.
The original shims are expensive and hard to get.
You can use Ducati 2V shims. You want 8mm opening shims -- do not use 7mm or closing shims.
See http://emsduc.com/product-category/individual-shims-and-half-rings/ to order, but Ducati shops should have them too.
See also: http://www.precisionshims.com.au/
(thanks to John Titus)