I suggest that you reset it to factory default to fix the problem.

read this method below:

Resetting the BlackBerry smartphone to factory defaults will erase all data from the BlackBerry smartphone (including built-in storage) along with any IT policies sent from a BlackBerry® Enterprise Server.

In addition, an applied BlackBerry ID will be removed, allowing the use of another.

Warning: It is recommended to backup all BlackBerry smartphone data prior to performing a reset to factory defaults to ensure the data is not permanently lost. You can perform a backup of the BlackBerry smartphone using KB12487.

For BlackBerry Desktop Software 6.1 to 7.1

These versions of BlackBerry Desktop Software have built-in functionality to perform a reset to factory defaults. To perform this task, please refer to KB27739 - How to use the BlackBerry Desktop Software Support Tools.
For BlackBerry Desktop Manager 4.7 to 5.0.1 and BlackBerry Desktop Software 6.0

On 32-bit Windows XP, Windows Vista, and Windows 7:

On the computer, click Start > Programs > Accessories > Command Prompt. (Note: Windows Vista and 7, right-click and select Run As Administrator.)
Type cd C:Program FilesCommon FilesResearch In MotionApploader and press Enter.
Type loader.exe /resettofactory and press Enter.

On 64-bit Windows XP, Windows Vista, and Windows 7:

On the computer, click Start > Programs > Accessories > Command Prompt. (Note: For Windows Vista and 7, right-click and select Run As Administrator.)
Type cd C:Program Files (x86)Common FilesResearch In MotionApploader and press Enter.
Type loader.exe /resettofactory and press Enter.

For BlackBerry Desktop Software 2.4 for Mac

Close the BlackBerry Desktop Software if it is open.
On the computer, click on Go > Applications > Utilities > Terminal.
Type cd /Applications/BlackBerry Desktop Software.app/Contents/MacOS/ and press Enter.
Type ./bbdm resettofactory and press Enter.

Note: If the smartphone has a password enabled, that password must be specified within the command line. For example, type " ./bbdm -password 12345 resettofactory" (where 12345 is the BlackBerry smartphone password).
For BlackBerry Enterprise Server 4.1

Open BlackBerry Manager.
Select BlackBerry Domain.
Click Edit Properties.
Select IT Policy.
Double-click IT Policies.
Select the appropriate IT policy or create a new one and click Properties.
Select Security.
Set the Reset to Factory Defaults on Wipe drop-down list to True.
Click OK to apply changes and exit.
Assign the IT policy to a BlackBerry smartphone user.
Right-click on the BlackBerry smartphone user and select Erase Data and Disable Handheld.

For BlackBerry® Enterprise Server 5.0

Log into the BlackBerry Administration Service with an account that can create or edit IT policies (for example, Enterprise Administrator or Security Administrator roles).
Under BlackBerry solution management, expand Policy, and click Create an IT policy (assign a name, click Save, then click the new IT policy name) or Manage IT policies, and select an IT policy to alter.
Click Edit IT policy.
Click the Security tab.
Set the Reset to Factory Defaults on Wipe drop-down list to True.
Click Save all.
Assign the IT policy to a BlackBerry smartphone user.
Select the PIN number of the BlackBerry smartphone user from Manage users and choose Delete all device data and disabled device.


Note: A shortcut may be used to avoid typing out the full string.

For a Mac, enter the first 3 letters of a specific folder, then press the Tab key: cd /App <Tab> will result in cd /Applications appearing on-screen.

For a PC, first type cd pro followed by the Tab key until it reads cd "C:Program Files". (Pressing the Tab key repeatedly also cycles through commands in alphabetical order.)

Stepping through the folders individually helps eliminate spelling mistakes and guarantees the folder is present.

The factory reset performs much like the Wipe Handheld option from the BlackBerry smartphone, with some minor differences.

Wipe Handheld - The Wipe Handheld option is performed directly on the BlackBerry smartphone (see KB02318 and KB14058). This option removes all BlackBerry application data (emails, address book entries, calendar events, etc.), and allows the deletion of User Installed Applications and the content of the Media Card.
Reset to Factory Defaults - Application data will be removed and so are IT Policies. Third-party programs will NOT be affected by this operation. They will remain intact.
source: www.blackberry.com/btsc/kb18998

if this didnt fix your problem, try bring it to your service center it might have a hardware problem. hope it helps.

Try a master reset back to factory settings, this information available on the blackberry website in the user manual section.

I`m having the exact same problem.. also tried updating to two diff OS (5 and 6v) ... any help is appreciated.

I recommend you reboot it: press and hold the alt, shift and delete keys. Then look for software updates.

Get on the net and go to blackberry. From here scroll to the 7th phrase of "problems with phone freezing...".

Seems that you need to tack out your sim and battery and leave it out for ten mins.

Remove battery. Reboot. Make sure all to check for updates once you restart.

Mine does the same...i just take the battery out and it seems to sort it out!

Go to your local phone dealer or read the manual by downloading it online.

Well, try taking it in to a phone shop and ask whats wrong.