Screen saver no longer asks for a password I'm using a MacBook Air 13" mid 2012 with Yosemite 10.10.3, it rebooted itself this morning without a reason and since then the screen saver is no longer asking for a password on unlock.

This is a great security flaw but I can't find a solution, I've tried modifying the security option by unchecking and checking everything again but it just does not work.

Anyone had this issue and know how to fix it? I use the device for work so it must always ask for a password before unlocking.
I've tried using backups and it did not solve the issues, after 3 reboots the problem disappeared without changing anything at all.

I don't know the reason or why it fixed itself with just several reboots, but seems a good solution.

I hope someone will discover the cause and a proper solution.