I have an old WD Passport USB drive I'm using solely for backups. Every now and then the drive disappears (despite having its own power source) resulting in an error message "this disk was not ejected properly" when Time Machine tries to perform a backup. The issue clears up after clicking away the error message and it backs up successfully, but it's getting tiring seeing this pop up once a day or so. Is there a way to suppress this message or keep the driving from annoyingly ejecting itself (or whatever the crap it's doing) at least until I have enough to spring for a new drive?