Have you tried removing the battery for 30 seconds?
What happened just prior to this happening? Any new apps installed? New themes? Did you drop the device? Did it come in contact with moisture (have it in the bathroom while you were in the shower, etc)?
__________________ The difference between stupidity and genius is that genius has its limits. When you take things for granted, the things you are granted, get taken. Even a mosquito doesn't get a pat on the back until it starts to work. Too many people miss the silver lining because they're expecting gold. [BES 5.0.3 / GroupWise 2012 HP2]
Mine had those problems for a while, dont worry it's only temorary.
Our if it's STILL happening, like he said, remove the battery for 30 seconds, our try rebooting. Thats the best thing that could help!