What program are you using to burn? I use ImgBurn with this same burner, and have one of those LG BD-RE disks that came with the drive. It takes a very long time to format a 25gb BD-RE disk, but it has to be a full format the first time the disk is used. ImgBurn will automatically do this format for you prior to your burn.
These particular BD-RE disks sold by LG don't seem to have a very good reputation, but I have successfully written to mine twice now.