Have been upgrading my recently purchased 5.1 Mac Pro with a few things (dual hex core CPU, RAM, SSD, USB3 etc). I replaced the superdrive with a Pioneer bluray drive and the drive tray now ejects every power on. The drive was installed about the same time as upgrading the OS to Mavericks, so not sure if the drive or OS is more relevant. Same thing happens with the drive in either slot and I haven't yet tried putting the superdrive back in place of the bluray drive. Apart from ejecting at power on, the drive seems to operate fine. After power on, I can just press the ^ key to close the tray. Just a bit annoying really. Other than that, this is my first MP (have a mini, rMBP, ipads etc) and I am really enjoying the quality of the engineering of the MP and the ease with which you can customise the machine. It just works, well mostly Any similar experiences or suggestions?