USB drive not mounting automatically - SOLVED
Several of us have recently had a problem with USB drives not being
automatically mounted for ordinary users. The solution _used to be_
to revert to the stable version of consolekit, but that has recently
failed too (at least for me). I'm not sure of all the underlying
reasons for it, but apparently the current consolekit changed the way
it dealt with permissions (for mounting drives, restarting the system,
etc.), requiring other system utilities to respond, among them the
display manager. I had been using xdm; changing to gdm as my default
DM (edit /etc/X11/ default-display-manager) has (for me, ymmv)
corrected the problem.
Hope that helps someone having the same problem.