The freezing then is likely due to some application you have loaded, or recently loaded.
You can reboot the device in Safe Mode and remove the app or theme.
-- Remove and reinsert the BlackBerry smartphone battery.
-- When the red LED (Light-Emitting Diode) goes out, press and hold the Escape key until the loading screen appears then release the Escape key.
-- When the Smartphone boots up the Safe Mode disclaimer listed below appears, click OK to dismiss the disclaimer. KB17877-How to start a BlackBerry smartphone in Safe Mode