I read that many have problems with mounting USB-disk and USB-flash memorys. They experience same issues as i.
It seems that this is something many others also experiences and that can be there is some sort of bug.
I have i feeling that this happes just after i connectet a USB-HD with NTFS and i used ntfsconf. Maybe ntfsconf did somthing that messed up automounting.
That may be a reason, bugs may exist for NTFS. Because all fine working usb drives i’m talking about are FAT32 (except one, my friends 200Gb external USB h/d which has FS NTFS). Check the permission of .hal-mtab.