This message from Shelby is very interesting. The issue is even more complex than what I believe it was.

The recent versions of the core wallet are only distributing adresses starting with 3. Do anyone know if its possible to generate adresses starting with 1? Most of my stash is on those old "legacy" adresses, but I dont know if any fractions that I move from adresses starting with 3 to these old adresses would be valid (in face of what Shelby explained, assuming its true). Any suggestions?