I have a iPod 20 GB connected through a usb 2.0 port. I use gtkpod to transfer files to it. It have worked like a charm so far. But one day i synced the ipod and noticed that i had forgoten some files. So I added the songs to gtkpod and presed sync, but this time it said that it couldn't write to the ipod, i can't delete files from the ipod either. When i trie to do it via the terminal I get an error messege saing the ipod is a read-only system.
The entry in fstab is
/dev/sda3 /ipod hfsplus rw,noauto 0 0
I have no idea what's gone wrong. Can anybody help me? It feels like i have tried everything.
BTW i have debian, Kernel version is 2.6.11-1-386

I think I had this same problem yesterday. dmesg said that the ipod's filesystem was not cleanly unmounted (I might have unplugged it without properly unmounting it) and that it was therefore being mounted as a read-only filesystem. After an hour of frustration and googling, I downloaded hfsplusutils (http://ftp.penguinppc.org/users/hasi/). Looking through my bash history, it looks like this fixed it:

# hpmount /dev/sda
# hpumount

You should then be able to mount and umount in the normal fashion.
Hope that helps.

I tried it but now I can't even mount my ipod any more i get this error messege: "mount: wrong fs type, bad option, bad superblock on /dev/sda3"
When i enter #hpumount i get this message "hpumount: destroy: Error while destroying .hfsplusvolume (No such file or directory)"
And all musik I had on it is gone. So if you know what i shall do now I would like to here it soon. I'm going away for two weeks and i would like to have some musik with me.
I have no idea what to do so please help me.

Now I can't even boot my ipod. So i guess that my ipod has to be repaired.

This so wierd. I'm also leaving for vacation and this happened to me twice last night. gtkpod froze during the middle of transfering music (I suspect it might be the hfsplus module) and I could not gracefully kill it, so did a eject /dev/sda. When I tried to mount it dmesg said the same old stuff about the filesystem being read-only so I took my own advice with hpmount /dev/sda and hpumount and I also corrupted my files....that's why I'm a n00b I guess! According to http://www.ipodlinux.org/Installatio..._Linux_Hfsplus, under "The Annoying Bug" heading, it seems you have to run this command when ipod is plugged in but not mounted. Mine must have been mounted because I've run these commands before and ipod was fine. Anyways, what you have to do is use a mac (if you still want to use the hfsplus filesystem) or windows box and go to http://www.apple.com/ipod/download/ to retore the firmware (you might also be able to do this with the cd that came with your ipod) I don't know about windows but on a mac this only takes a few minutes. This reformats the ipod, so you will need to put all of your music back on. Also, the ipodlinux.org article mentions how to back up the ipod to a (big) disk image so if your ipod's filesystem does become corrupted again, you can retore it without having to find a windoze or mac machine.