For what it is worth and I doubt it should be taken seriously.
Clarin, one of the the national Argentine newspapers is reporting as follows.(rough translation)
One of the aeroplanes was authorised by the tower at Brasilia to fly at 37000 feet,the other was authorised by Manaos to climb from 35000 feet to 39000 feet and that the collision was caused by a lack of communication between the "towers"
Make of it what you will, I just thought you may want to see what's being reported down that way.