Strangely broken git repo

Hi!

We are having strange problems pushing (and pulling) with a particular head in a git repo. The repo is publicly available via http, and when I clone it it gives me a lot of errors

$ cg-clone http://locke.catalyst.net.nz/git/moodle.git#moodle--topnz
...
Getting index for pack 3e3492f365bb0d4a1ae11dfa7cee9ebbf345e647
Getting pack 3113eb34ef85482c87c3575721ce978c7232071f
which contains 007a0323cf0941476dc262f6e3aff6bb9600dcd8
error: The requested file was not found
... (many more like these)
FINISHED --15:56:38--
Downloaded: 4,723 bytes in 1 files
New branch: 6759e2800c0cef00017c63b7dbbed80e481dbe2c
Cloned to moodle.git#moodle--topnz/ (origin
http://locke.catalyst.net.nz/git/moodle.git#moodle--topnz available as
branch "origin")
aporo:~/tmp/moodle.git#moodle--topnz martin$ git-fsck-objects
bad sha1 file: .git/objects/00/7a0323cf0941476dc262f6e3aff6bb9600dcd8.temp
... (many more like these)

When using git+ssh, we are seeing very strange stalls during the fetch, and when trying to push a couple of small new commits, it has given us (from a Debian etch-ppc, git 0.99.8.b) gives us "fatal unpack should have generated <sha1> but I can't find it".

This has been discussed earlier here http://www.gelato.unsw.edu.au/archives/git/0508/7152.html -- but our scenario doesn't involve rewinding or any strange trickery, it's just clone - edit - commit - push.

 From a different machine (Debian sarge, i386, git 0.99.8b) the same
operation succeeds.

On the repo itself, I've run git-fsck-objects --full --strict and it only complained about dangling tags. There are some heads on that repo that I have deleted a while ago without purging unreachable objects, so I kind of expected those.

There are some automated jobs that touch this repo and may have messed
things up:
  - cronjobs running git-cvsimport and git-archimport and pushing to 
this repo
  - weekly git-repack run over the repo

Uff. I have the feeling that this isn't a very complete picture, but I'm not sure what else to do to debug this one. Pointers welcome.

cheers,

martin