Yeah. If your card is full from other saves, it won't save high scores. You may have to change the name of the memory card to end in an exclamation point to enable high score saves. From what I remember, NeoSaveMastas come with this preset.
Replacing isn't limited to swapping the old one with a new one. It can also mean putting back the battery even if it was taken out some time ago. This behavior is typical of a board missing or having an inoperative battery.
This is a good beginner soldering iron if you don't want to spend too much. I can solder tsop and qfp with the stock tip.