Flash memory have limited amounts of writes before they break. Used to be in the low thousands for the same block. Newer flash memory devices (most anyways) have built in RAIDed banks and will automatically detect memory going bad and remap it. PS1 probably predates any features like that... so the more you save to it, the quicker it will wear out.
I hope they did the memory in the wii right... otherwise in a couple of years it will be as bad a rrod...








