Apple just passed along this statement, addressing the Snow Leopard user account bug that eats your user account.
https://gizmodo.com/reports-snow-leopard-bug-eats-user-accounts-whole-5379817
We are aware of the issue, which occurs only in extremely rare cases, and we are working on a fix.
And yeah, it’s obvious that it is a pretty rare bug, since you’d have heard about this bug on day one if it wasn’t.
