After updating linux headers from 3.5.0-19 into 3.5.0-20 i faced booting problem. I don't know reason, sometimes boots normally, but sometimes i need to reboot 3-4 times. I tried to boot with recovery mode, but i didn't see any error there. But with 3.5.0-19 linux boots normally. What's the problem with 3.5.0-20?