Unknown error 3002 occurred when updating iPad

Hello all
Recently apple launched its iOS 5 so I decided to update my iPad.
When I opened iTunes to update my devices and started updating the software, I got an error and the device was not updated.
The screenshot of the error is as follows:

iTunes
The iPad 'iPad' could not be updated. An unknown error occurred (3002).
What can I do to solve this issue? I have really been waiting for this update but now I am facing this issue?
Please help me out to solve it as early as you can, I'll be really grateful.
Waiting for your replies
Regards
