Blackberry 9800 backup shows error

I wanted to back up my Blackberry 9800 using Blackberry’s Desktop Software, but whenever I try to backup media files an error pops up with a message is that there is a connection problem or a problem with the device. It is on and connected. Below is a screenshot of the error message.

Error message:
There was an error backing up.
There could have been a problem with the device or connection during the backup. Verify that the device is turned on and connected.
