Lingzhu Xiang wrote: > Libusb explains LIBUSB_ERROR_PIPE with "control not supported". But I don't > understand how it could be randomly working and not working, if something is > really not supported from the beginning. The device is good. I tested it under > Windows with Argyll spotread. I also tried it with different USB ports or with > reboots or with kernel 3.1, no success. Hi, this seems like something interfering with the USB, or a bug in the USB stack. I'm not quite sure what that would be though. You could make sure that libmtp is not running (started in udev), as it has been known to interfere with instrument USB access. Graeme Gill.