Hi all, first post so please don't hurt me.
I have a Go Video/Sensory Science R6740 with the P.O.S. Lite On DDW-451s drive installed in it. Recently it refused to read +R discs and will not record +RW discs. I tried the LDW-851s I've had for a couple of years from one of my PC's and it worked immediately without any firmware update. Complete functionality has been restored!
I just ordered a new Lite On DVD burner from Newegg for the PC I will take the 851s out of. Hopefully I will be able to easily interchange the drives so the 851s won't be outside of the R6740 case - I will do this if necessary. It is really great that the DVD burner can be replaced. I've never had any problem with the 851s at all - I've burned over 200 discs with it and I used the 451s sparingly - nothing on TV. Go figure.