Tearing my hair out here, been using my 1TB WD for last two years as time machine with no problems and very fast. Just updated to El Capitan and try to backup but it runs for 10 minutes or so and then I get the message disc not ejected properly. However many times I try this it keeps kicking it out. fine before upgrade but now shortly after, no joy. Tried different ports but all give the same result. Any help most grateful. The other strange action is when the mac wakes, keyboard typing seems to go wild with random characters as if the keys are stuck. I have to restart to et back to normal. Thins getting really annoying.