Welcome to the Official BlackBerry Support Community Forums. This is your resource to discuss support topics with your peers, and learn from each other. New to the forum? Please visit the ‘Getting Started’ link below.
I generally have that happen when I load a lot of stuff onto my blackberry. Remove the battery, let it sit for a minute, and then put it back in. Then give it a couple minutes to just load itself up and it may fix the problem. May be something else though, who knows.