i got problem with my ps3 as well....i was playing fifa 11, but suddenly it hanged. i tried to restart my ps3 and play fifa again, and it hanged again.
i googled, and found out a lot of user complaining as well. it's all happened after they got 3.61 update. They tried reboot and reboot again but it same as me, their ps3 also hanged. and after a few attempt their ps3 kena YLOD. scared mine also kena YLOD i stopped turning on my ps3 until i found out whats really happening.