im sure i could word the title better.... i have a 2009 mac mini connected to my tv which among other things runs a plex server. so if i download a movie or tv episode, its downloaded on my imac, and then i click on the mini and then the external usb drive, and drag the file onto it for it to copy into my movies or tv folders. recently, i often (but not always) have a problem where when i click into the mini i only see the internal SD drive, not the external usb drive. the drive works fine. weirdly if i click on screen sharing i can see the drive on the mini's screen and drag the file onto that and it works fine but slower. in file sharing the external drive is markes as sharing for all users, and it does appear sometimes, and it used to appear every time. any ideas?