That's... vauge. But it might be that the cart's battery backup is dead. I'm not sure how you go about getting a new one, but a good google for "Gameboy battery replacement" might help.
My friend IJD GAF (not his real name) has the same problem with his Metroid II cart. Mine did okay most of the way through, but every time I killed the Metroid Queen, it would freeze up. Switching to an AC adapter fixed that problem -- you might want to give that a try, radu.
Oh, and Gameboy carts have a tendency to randomly arase games after awhile. Donkey Kong Land does it to me. My copy of Warlocked for GBC does the same thing on occasion.
check out the favicon topic. that thing is screaming.
I know. Hence the whole "night of the living simu-posts" thing. Though I guess it's more the "mid-afternoon of the living simu-posts" for you Americans.
yep, my donkey knog for n64 erases my games, and then reloads then like after a month and my donkey knog for gb doesnt save anymore, and i tried to sell it to gamestop but they only offered 36 cents for it, so i kept it :P