last time i was trying to reformat mydocs to ext3, but I failed and had to reflash device because everything went wrong and here is what i've done: i backuped data. i umounted myDocs. I changed its id to ext3 by fsdisk. then i partitioned it by mkfs.ext3 then I mounted it and restored files. finally I rebooted device... there weren't letters just boxes and whole motif was crahed. then my nokia rebooted and so on. do you know what havent i done?

I had the same problem with ext4. Any info would be nice

Have you been following this? http://wiki.maemo.org/User:Ruskie#Repartitioning

Or just boldly tried it out on your own?

In the latter case, you'd like to show us the commands you used.

I would check out first http://wiki.maemo.org/Repartitioning_the_flash
and in particular the references to /usr/lib/genfstab.awk
where Mydocs is hardcoded to vfat.