I choose now Debian Lenny !
But I have before another problem and I don't know if the two are connected.
This is my problem :
I am forced to format my card on my pc with gparted like that :
/boot 200Mo ext2
/ 3150Mo ext3
512Mo Linux-swap
I copy uImage and uInitrd on /
When a reboot the SheevaPlug, I loal the 2 images, start internet connexion. If I want format the ext3 partition, I can't : it failed

(with 2 differents SD card of 4 GB). So, my solution is to not format the ext3 and it's ok, the packages can be downloaded. But there is my error message of corrup package for exemple

My connection is (I think) ok, I use it all the day with other downloads, why it can't be good now ??
Help help !