Hi dave32,
just because the file ends in dra does not make it a Dragon Cam file, only Predator files are used to upgrade the dragon cams firmware. I am unaware of this file, it might be for Joker cams, it might just be a fake file or it could be a malicious file. If you're relatively new to the Dragon Cam I advise you to read the files in the Predator folder and, as advised, use the DCP checker, to check any files before loading them onto your Cam, also only use trusted sites for updates:
http://www.satellites.co.uk/php-bin/forum/showthread.php?t=11174
The DCP checker is easy to use, just click on the paper symbol and navigate to your .dra file, if you get a green dragon it should be fine if you get a red dragon do not use it.
Best wishes
Mickha