I suspect that there is something wrong with the NAND Flash of my C1000. So I installed OZ/GPE 3.5.4.1. In dmesg I saw these:
Empty flash at 0x0062bfa0 ends at 0x0062cf00
...
And A LOT OF similar messages. Does this mean my Flash is broken?!
I did the "NAND Flash (All)" test on the "Zaurus Test" Menu in DM and it were all OK, though.