Blackberry Curve flashes white and then takes me to hourglass

[Decept125]

My blackberry curve 8530 randomly just flashes white and quickly fades away and then takes me to a black screen with an hour glass, and then it flashes white again, and it does that over and over again.

It works though when I plug it in my computer and update the device software using the desktop program or whenever I reboot the software. Does it need a new battery? Because it only happens during certain times like when I get far into a game or I delete a video on the phone. It's fully charged too.

Please help and happy holidays!