Marek,
Thank you for keeping us informed about your discoveries. I hope that as they promised, the new software release will fix some of these problems. It is pretty disappointing to read about the lack of flash memory (I can not see a way to solve this problem with the sofware revisions, unless they introduce a Disk Link function like Roland).
Please let us know about your further impressions of this keyboard - this is the type of information that one can not learn from playing with an instrument for an hour in the store.
Best regards