We talked to digikey.com (our distributor) and they played the ball back to digi:
Their answer (in short) was:
"I cannot help much further, ... they should fully test out their software whenever a new software/hardware revision is announced. I think that there is no way to influence the revision they order as we cannot track the software when it is not mentioned on the paperwork from Digi International ... "
And regarding to downgrade the software: "then they need to take care of this preventive action on their own."
Well, this is not exactly the answer i was hoping for
But, how should they answer these questions ? they are distributor, not manufacturer.