There is no R4ED001 MAIN GENERIC RED50. It is the R4EA031 MAIN GENERIC file that you want.
Although, that being said, I'm getting the same error, but I think that may be because of a funky file, bad driver, or I'm using the wrong cable.
I'm using the standard USB cable that came with the phone. I don't think it's the DCU-60, which is probably why it isn't working. So when I get around to getting it, I'll give it a shot.
btw, I'm using a ROGERS wireless w810i, red50.
Also, don't forget to backup your GDFS