git repack memory limit

I am running git-repack on a server with memory limits. I am seeing the
repack spending 400MB and going out of memory. I could not limit repack
memory usage in anyway. I tried:

git config pack.deltaCacheLimit 1
git config pack.deltaCacheSize 1
git config pack.windowMemory 32m

then git repack -a -f -d

also I would particularly expect git repack -a -f -d --window-memory=16
to succeed.

Using git 1.6.5. Any thoughts?

-- 
Bahadir