I have a very strange error with my Legend of Zelda cartridge.

The game starts fine (with a bit of blowing / cleaning - I have to do that with most games and am probably going to replace the 72-pin soon). You can start it, play it, delete saves, restore saves - nothing wrong with the battery at all.

BUT

The displayed "count" for the three items at the top (rupees, keys, and bombs) stays at zero. You can pick up these items in the game - you get rupees, can spend them, and get bombs, and use them, and get keys and unlock doors. It appears to count the appropriate number, too - if you get four bombs, you can use four bombs. It just won't show you how many you have - it always says you have zero.

What could possibly be going on with this? It's bizarre.