I've got the same problem. Apparently the 5g's running 1.2 Firmware have a problem being detected by ipodpatcher, which si where you get that "Parameter is incorrect" error. I get it too only when using ipodpatcher 1, and I've tried 0-30. 0 is my main hard drive, 1 is the ipod.
There's a fix to this posted in another forum, but from what i've been told, Rockbox will have to be adapted to the 2048bit sector size in the new firmware. (If I'm wrong someone, please correct me... I'm still somewhat new to this =)
If there's anything I can do to help, feel free to message me. I've got a new 5g with the 1.2 FW installed, and i'm desperate to get away from iTunes.
And how do you just "repatch the bootloader" so that you can get it to work on a 5g with 1.2 as listed below?
Ok. I guess I'll just sit tight and hope for an update that will fix things for me. I'm still a little confused as to what exactly I did/didn't do to cause the problem, but thanks for your help. I'll try looking more into 'Error reading from disk: The parameter is incorrect'.
*edit* homelow says ((http://forums.rockbox.org/index.php?topic=6475.msg51075#msg51075):
to fix rockbox on the 5G with firmware 1.2 just repatch the bootloader, (with iPodlinux you have to go into linux(live CD or otherwise) and redefine the partition table) the Apple installer overwrites it as FAT32 to which mrmagic526 says
Yes that's all you need to do is extract the new firmware patch it and then reload it and it works
Unfortunately I don't know what it means to 'repatch the bootloader'. Could someone enlighten me on that?