Sheevaplug Kernel packages - backports.org vs people.debian.org/~tbm/orion vs tbm snapshots

[debian.arm.nospam@sub.noloop.net]

Hello list,

for a Sheevaplug, what is the difference between the linux-image-kirkwood
packages on backports.org (lenny-backports) vs. the
people.debian.org/~tbm/orion repository (vs the snapshots announced
here on the list)?

Are the bpo kernels maintained by the same person(s) maintaining the
p.d.o/~tbm/orion ones? Currently I'm running a snapshot kernel on
one sheevaplug and a bpo kernel on another, and occasionally
apt-get wants to "upgrade" to a different repository, so I'm unsure
what exactly the difference is. For example, right now backports
has version "2.6.30-6~bpo50+1" which ~tbm has "2.6.30-8".

Thanks!