MTP devices, udev and permissions in Ubuntu Dapper

I had to install Gnomad2 in Ubuntu Dapper in order to upload files to my MTP Mp3 player.

I followed this great How To

However Gnomad2 could not open the device unless I was root (same thing for mtp-detect)

It looked like a permission problem in /dev/bus/usb

This worked for me :

In /etc/udev/rules.d/40-permissions.rules I changed

# USB devices (usbfs replacement)
SUBSYSTEM=="usb_device", MODE="0664"
to

# USB devices (usbfs replacement)
SUBSYSTEM=="usb_device", MODE="0664", GROUP="plugdev"

Then

sudo /etc/init.d/udev restart