Hi Naofumi,
We are suspecting that these issues are caused by a UART issue that the non Rev F and Rev H parts have. We have some Rev F parts now and we can verify if this is indeed causing the issue that you are seeing by comparing the behavior of the same code with different parts.
I have also asked Mikael and would like to request you as well. We may have to get a sample binary/code from you that is able to reproduce this issue if possible. If not we will need some detailed instructions for reproducing so that we are sure that we are seeing the exact same issue that you are seeing and compare the behavior with different parts. Last night we sent 100MB data from our Rev D to a windows SPP server and it did not show any error. So we may need your help to reproduce the exact issue that you are seeing. Please let us know if it is possible.
Thanks,
Stonestreet One.