Hi Oscar M,
Maybe we did not answer your question?
The sample devices that you obtained from the website free-of-charge come from the same stock that you would buy from a distributor. I guarantee that we are not giving away faulty devices.
You do not say if the parts that you got were marked "PC" or "MC", but your description of your problem was "the same code does not work".
It would be helpful if you can tell us the following information:
1) Full part number of "working device"
2) Full part number of "not working device"
3) Maskset number on both devices - this should be a 5character number etched onto the device, eg 1M40L
4) More full description of the problem.
I'm guessing that you have an "A" vs a non-A silicon problem.
Good luck,
Mark