Keep getting "Your systems hard disk's file system is corrupted" after upgraded to CFW

I am currently on CFW Overflow 4.82 v4 cobra 7.3 CEX. Everytime when I turn off my PS3 using the power button/ using the controller/ from the XMB, I will always get "Your systems hard disk's file system is corrupted" after my next boot and I will have to enter the safe mode and format the harddisk. I have tried to unmount the game and I still get this. Is there any potential cause to this and Is there any way to fix that?

Thanks!