did you get to the end of this? I have a BDP-S350 as well, rips work ok on BD-RE discs, but just ordered some 25GB & 50GB discs so wanted to know if you got this sorted.
Problem solved, the burner was not preforming the disc end finallize correctly. So i guess the Sony was just being picky as the other players had no problem. So make sure you end your burn with close or finalize the disc and you will be fine.