Here are the steps I've made:
- Pokemon Heart Gold is completed, all 16 badges, have the National dex, reached Pal Park in Fuschia city, and had the guy explaining to me how to use it.
- Pokemon Emerald is also completed, the Elite 4 is beaten, National dex is obtained, and battle frontier is unlocked.
- I insert both into my DS Lite, the opening screen shows both.
- I enter HG and in the start menu, the Migrate From option won't appear. I've scrolled down.
Heart Gold is EU and Emerald is US, I've read that it shouldn't matter as long as they are both the same language (for example, here and here).
I can play Emerald just fine on the DS, as well as HG. Other games of the 3rd generation give the same symptoms (although, I haven't completed those).
What might cause this phenomenon? What have I missed?