"error ejecting /dev/sdb" in nautilus (Garmin GPS)

[Adam Funk]

I have a Garmin Etrex 10 GPS that works very well with Ubuntu except
that every time I eject it in the GUI (nautilus), I get this error:

  Unable to eject GARMIN

  Error ejecting /dev/sdb: Command-line `eject "/dev/sdb"' exited with
  non-zero exit status 1: eject: unable to eject, last error: Invalid
  argument

but it seems to have worked anyway (GARMIN disappears from nautilus, I
unplug it, no data corruption).  Any ideas as to what's causing this,
& how to fix it?

Thanks,
Adam