I am running the latest Arch Linux Arm on a PogoPlug B01. Pacman reports everything is up to date.
When I upgraded Netatalk from 18.104.22.168 to 22.214.171.124, my 10.7.5 Lion installation was unable to find my Time Machine drive. Another Mac running 10.6.8 was able to find and complete a Time Machine backup.
If I went to afp:\192.168.1.77 or afp:\PogoPlug, I could mount my drives, but even with them mounted Time Machine failed to locate my backup drive.
I downgraded Netatalk back to 126.96.36.199 (pacman -U /var/cache/pacman/pkg/netatalk-3.0.1-3-arm.pkg.tar.xz) and my Lion installation was immediately able to perform and complete a Time Machine backup.
Let me know if you need any files or want me to try anything.