The thing to remember is that according to Nintendo?s specifications, a Pak can only have one function. In other words, the N64 can only see a Memory Pak or a Rumble Pak - not both. The way that the Mad Catz Advanced Force Pack+ gets around this is by having the different functions all built into the same device physically, with a switch that?s used to select which function you wish to use. If you have the Force Pack+ installed and you want to save your game, the N64 will not see it as a memory card unless the switch is set to Save. This can be a rude surprise when your N64 tells you that you don?t have a Memory Pak installed, and you know it?s there. By the same token, if you want to use the Rumble Pak feature, when the game says to insert the Rumble Pak if you wish to use one, you simply flip the switch to either High or Low (wimp). As long as you remember that, there?s no problem. Oh - and if it doesn?t rumble, make sure you have good batteries in it.