Okay, so after upgrading to Yosemite, my Mac mini turns Bluetooth on by itself even though I have it turned off. This was never an issue with Mavericks, has anyone else seen similar behaviour? It doesn't happen straight away but every time I come back to the mini after disabling Bluetooth, it is running again.
My Mac mini is connected via HDMI to a monitor and I have a Bluetooth keyboard and trackpad for when I'm sitting at the mini itself but typically disable Bluetooth as I normally access the mini remotely and may go 2 or 3 days without actually sitting at the mini - this is why I prefer to disable Bluetooth as it helps to preserve the battery life of the keyboard and trackpad.
My Mac mini is connected via HDMI to a monitor and I have a Bluetooth keyboard and trackpad for when I'm sitting at the mini itself but typically disable Bluetooth as I normally access the mini remotely and may go 2 or 3 days without actually sitting at the mini - this is why I prefer to disable Bluetooth as it helps to preserve the battery life of the keyboard and trackpad.