sorry for bothering again.
i just noticed in the firmware that you linked in your first comment, there is a memory expansion item in the system menu,
since it can use an ext2 usb mass storage device that is the first inserted into USB. wouldnt it also make sense to be able to use an ext2 formatted SD Card with the built-in SDCardHolder?
since it always has the same device name and is kinda ... harder to remove?
Keep up the good work!