Having problems mounting disks? Both .img files and removable media? Take a look at your /etc/hostconfig file. It should be about 27 lines or so. Does it contain the line "AUTODISKMOUNT=-REMOVABLE-"? If the file fails either of these tests, it may be corrupt. How might this happen? Probably due to a System Preferences crash or general disk corruption. If you'd like a clean copy to restore with, along with instructions on how to do so, read the rest of this article.
You'll have to have root privileges to fix this file. The easiest way to do this is to first 'cd /etc' then type 'sudo cp hostconfig hostconfig.bad' (in case we want to go backwards, we'll make a copy) then 'sudo rm hostconfig' (to get rid of the bad one), and finally, 'sudo pico hostconfig' (you'll need to enter your password on the first 'sudo'). This will put you in pico, the simplest of the command line editors. Once there, copy and paste the following text, save the change, and quit pico. I'm not sure whether you'll need to logout and/or restart, but it can't hurt.
COPY EVERYTHING BELOW THE DOTTED LINE:
--------------------------------------
##
# /etc/hostconfig
##
# This file is maintained by the system control panels
##
# Network configuration
HOSTNAME=-AUTOMATIC-
ROUTER=-AUTOMATIC-
# Services
AFPSERVER=-NO-
APPLETALK=en0
AUTHSERVER=-NO-
AUTOCONFIG=-YES-
AUTODISKMOUNT=-REMOVABLE-
AUTOMOUNT=-YES-
CONFIGSERVER=-NO-
IPFORWARDING=-NO-
MAILSERVER=-NO-
MANAGEMENTSERVER=-NO-
NETBOOTSERVER=-NO-
NISDOMAIN=-NO-
TIMESYNC=-NO-
QTSSERVER=-NO-
SSHSERVER=-NO-
WEBSERVER=-NO-
APPLETALK_HOSTNAME="My Mac"
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