Set warioland 2 to eeprom as safetype.
There was a black gbc and a grey gb cardridge, depends on thenrom you have the wrong safetype.
If i use a original black modul, do not switch your Plattform(GB to GBC..etc) the savegame will be deleted.
I will check in the next update. Focusing atm to fix the rtc time issue in pokemon prism and try to fix crystal to run.
But i'll check, uploaded my 1.2b a few minutes ago.
It's an old thread, so sorry for gravedigging.
But i run in these saveissue yesterday and it feels sad to press L+R so finalize the save.
So i fixed it in jagoomba:
https://github.com/Excalica/Exjagoombacolor
Now you can save directly without...