I don't have any of the older firmware updates available. However, what I can suggest is having the unit serviced. If it doesn't play either media, it may be an issue with the player itself.
I would recommend calling 800-SAMSUNG and having your unit serviced.
I just purchased a Samsung BD-P1500 from Walmart about three months ago. I just purchased Up as well as Star Trek on BluRay and the discs could not be read on my BluRay player. I then updated to the latest firmware on my Samsung BD-P1500 and now no discs (including regular DVDs) will play at all. I get the ever so famous Disc Cannot Be Read error message. Is there a way to downgrade the firmware update or am I stuck with a Samsung paperweight?!?!? When is there going to be compatibility with Star Trek and Up?