I'm using kde but when insert the USB external hd, it detects automatically but when i open it, it reply
hal-storage-mount-removable-extra-options auth_self_keep_always <-- (action, result)
So manually mount the HD enables me to read the contents inside the hard disk but as root user.
Anyway, learning to mount using root account and make it available to all users is something new i can learn and i'm quite looking forward to the solutions for this issue. So i do not really bother why it cannot automatically detect previously.
Since i'm asking this question, i might as well ask y it prompt this error when i plug in my HD?