I have bought a second hand GP32 FLU, including 2 SMC's of 128 MB and 4 commercial games. They aren't boxed, but came from JoyGP (Entware), so they are encrypted.
I re-registered my GP32 FLU on GamePark.com and JoyGP (Entware). Afterwards, I'm not able to start any of those 4 commercial games...