04-11-2013 11:28 AM
Hi and Welcome to the Community!
Anytime random strange behavior or sluggishness creeps in, the first thing to do is a battery pop reboot. With power ON, remove the back cover and pull out the battery. Wait about a minute then replace the battery and cover. Power up and wait patiently through the long reboot -- ~5 minutes. See if things have returned to good operation. Like all computing devices, BB's suffer from memory leaks and such...with a hard reboot being the best cure.
Otherwise, I recommend that you attempt to boot into Safe Mode:
It may take you multiple attempts to get the ESC key sequence (press/release/hold) correct, so be patient. When successfully into Safe Mode, think carefully...what happened just before this behavior started? A new app? An update? A Theme? Something else? Think carefully as the smallest change could be causal...and attempt to undo whatever that was.
Good luck and let us know!