Does anyone here own a Blackberry?

Both my kids have a Curve 8520 and my daughters phone has crashed and we cannot get it working again. The phone started re-booting itself a couple of days ago with the screen turning white before going on a re-boot again. It got stuck in that loop and wouldn't do anything. Now the screen is permenantly white and the message reads "Reload Software: 507".

I have tried re-loading the software via the Blackberry desktop manager and their official website but where the phone keeps re-booting the download stops and the PC message reads "Fatal Error" halfway through the download.

The various websites and forums I have visited all start off with "have you removed the battery and put it back in?". Yes, we have done that and it makes no difference.

Has anyone else experienced this and if so, were you able to find a fix?