Thomas Kunze provided newer version of his SD/MMC driver some time ago. Today I finally got some time to test it.
Result is awesome as most of my cards works now — only RS-MMC from Nokia 770 does not want to behave. I posted logs into proper bugraport and Thomas told:
hrw: fine. so nearly all cards work now. I have an idea what your rsmmc might need.
So it looks like this one will work too soon. New test images for Ångström will be available probably tomorrow.