My advice, do a clean reinstallation of the device software. See the following. KB11320-How to perform a clean reload of the BlackBerry Device Software using BlackBerry Desktop Software for Windows
There are some things you could try first, but I'm guessing you would be better off starting over clean.
Some tips: Do a full backup first, just in case. After you reinstall the OS, only reinstall the apps that you absolutely need, and watch your free memory. Posted via BlackBerryForums.com Mobile