Are these issues documented anywhere?
Search this forum. While there are issues and questions about NativeEthernet, they don't include the kind of crash you were seeing. I think you'll find that the issue is not NativeEthernet per se, but something related to your initialization and/or use of it. I recommend looking at QNEthernet because it does solve some of the known issues with NativeEthernet, and the developer seems very motivated to help people who want to use it.