I've noticed that after all this time, many of the PSR2000 advertisements still state that the OS is in Flash Rom. We know that this simply isn't true.
It is a great keyboard for the money, but upgrading really isn't an option.
Musician's Friend has it in their catalog and on their website this way, as does Sweetwater Sound, and I'm sure it is that way in other places.
Just another reason to patronize "our own" dealers, such as George Kaye and DanO. They will not misrepresent anything and will be there to help after the sale.
DonM