1.55 Final runs Scribblenauts just fine. In fact, the only game it doesn't run is Mario and Luigi.
1.56b1 was created to fix M&L, but it broke Scribblenauts and a few other games (Grand Theft Auto).
1.56b2 fixed Scribblenauts and the other games that 1.56b1 broke, but it broke Pokemon Platinum and I guess a few other games too. However, both Scribblenauts and M&L worked so I was happy with this firmware.
1.56b3 fixed Platinum and some other games. I don't know what other games that this firmware broke, if any, but people have reported that Heart Gold/Soul Silver lags a bit when entering/leaving buildings.