If anyone is interested...here's the source code as to why the Zunes all crashed.
while (days > 365)
{
if (IsLeapYear(year))
{
if (days > 366)
{
days -= 366;
year += 1;
}
}
else
{
days -= 365;
year += 1;
}
}
Basically, who ever programmed this part of the Zune didn't put in while (days >= 365). So when it became December 31st (day 365) it got stuck since they did not include that final day into their loop statement. I believe this method was for checking to see if the year was a leap year or not. Which ever Zune owners had this version of the firmware got a very unhappy surprise on December 31st!