I think it was more the case that there were unknown issues with the coding that came to light once the machines were being played in countries with 50hz power.  Stern have fixed the code and by all reports, the bug has been fixed within the week.  To their credit, AMD refused to release their machines until the issue was sorted so as to avoid any potential damage to the machines and keep all warranties intact.  Some other re-sellers weren't as thorough as AMD and released machines basically untested and put those machines at potential risk.