subway:
To make matters worse each shipment of parts not only had bugs but different bugs requiring a hardware and software change for each shipment. This may not be a big problem for a hobbyist but it’s a disaster for a company that wants to put its product into production.
I seem to recall an EEVblog about PIC chips also having bugs.
Ah yes, here:
Title: "EEVblog #53 – Mr Murphy and Microchip PIC Silicon Bugs".
In the middle of the episode he finds that one of the sets of the ICSP programming pins are not connected internally in the chip! And that was the one he chose to wire up on his board.
So it's not just Atmel that have production problems.