Thank you for the reply. In my case, I am not (yet) using U2F. I'm using OTP + CCID.
For some reason, I'm now also seeing similar behavior on my Mac. When I insert the key, it lights up for a few seconds and then goes dark. I see this in the system log:
Code:
11/3/14 09:34:23.684 com.apple.SecurityServer[53]: Token reader Yubico Yubikey NEO OTP+CCID inserted into system
11/3/14 09:34:23.684 com.apple.SecurityServer[53]: reader Yubico Yubikey NEO OTP+CCID: state changed 0 -> 34
11/3/14 09:34:23.684 com.apple.SecurityServer[53]: token in reader Yubico Yubikey NEO OTP+CCID cannot be used (error 229)
11/3/14 09:34:24.000 kernel[0]: AppleUSBMultitouchDriver::message - kIOUSBMessagePortHasBeenReset.
11/3/14 09:34:24.000 kernel[0]: AppleUSBMultitouchDriver::checkStatus - received Status Packet, Payload 2: device was reinitialized
11/3/14 09:34:24.405 hidd[70]: MultitouchHID: device bootloaded
11/3/14 09:34:24.000 kernel[0]: AppleUSBMultitouchDriver::_deviceGetReport - DeviceRequest for reportID 0xc8 returned with result 0xe000404f - retrying
When I revert the key to only doing OTP, the problems go away. I insert the key, and it stays lit up.