Since it appears to be a difficult to reproduce problem here, those who observe this could help....
Apparently there are other cores where those big cards work, when they do not work in the turbo chameleon core - i'd like to know exactly what cores those are (please link to the exact version/binary). Please also tell if you have a v1 or v2 chameleon, and in what slot you installed the other core. Please also tell what kind of SD card you are using (and preferably post a picture of front and back side). And to make it easier to reproduce 1:1, please try with a fresh sd card with minimal contents needed - and tell what those contents are. I'll have to investigate in detail what the other core is doing differently (in the core and the software running on it), and perhaps Jens needs to do some measurements too.
