I do not know if this is relevant, or not, as I'm still sort of a linux rookie. But I just solved an issue with an USB-drive (1TB for backups) connected to my GuruPlug and fstab.
I could not get it to work when adding it in /etc/fstab since it borked on boot-up with errors, I tried this script and various other tweaks but to no avail.
The solution? Remove the usbmount package, now it boots/mounts just fine without any scripts/hacks =)