I recently bought a Sony e-reader, the main Linux package to support this is calibre but I found that it wouldn’t automatically sync my ebooks.
"The linux kernel can export two version of SYSFS, one of which is deprecated."
Apparently Debian Lenny exports the deprecated version and you have to recompile the kernel to undo this.
I wanted to make the minimum change possible to my system and continue using the packaging system : I follwed roughly the following steps:
sudo aptitude install kernel-package ncurses-dev fakeroot wget bzip2 linux-source-2.6.26
tar -xjf /usr/src/linux-source-2.6.26.tar.bz2
cp /boot/config-2.6.26-2-686 .config
In the config menu I selected
General setup –>  Create deprecated sysfs layout for older userspace tools
And made sure I specified a custom revision to differentiate my custom package from the standard one
make-kpkg –rootcmd fakeroot –initrd –revision=custom.001 kernel_image kernel_headers
sudo dpkg -i linux*deb
Then reboot ensuring the new kernel is loaded.
I meant to write this up as I went but I’m doing it a few days later so please take care if following them - and adjust to suit your kernel version etc.
The above sounds like a pain but was actually fairly easy, and calibre is much better than the official Sony software which I tried on a Windows machine but it was slow and kept crashing.