Problem with http access to stable git - linux-2.6.23.y

[Richard MUSIL <richard.musil@st.com>]

I am experiencing problem when accessing 2.6.23.y stable git over http.
In my config I have:

[core]
        repositoryformatversion = 0
        filemode = true
        bare = false
        logallrefupdates = true
[remote "origin"]
        url = http://www.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
        fetch = +refs/heads/*:refs/remotes/origin/*
[branch "master"]
        remote = origin
        merge = refs/heads/master
[remote "linux-2.6.22.y"]
        url = http://www.kernel.org/pub/scm/linux/kernel/git/stable/linux-2.6.22.y.git
        fetch = +refs/heads/*:refs/remotes/linux-2.6.22.y/*
[remote "linux-2.6.23.y"]
        url = http://www.kernel.org/pub/scm/linux/kernel/git/stable/linux-2.6.23.y.git
        fetch = +refs/heads/*:refs/remotes/linux-2.6.23.y/*

Which basically means I am cloning Linus' git and fetching stable branches.
For linux-2.6.22.y it has been working fine so far, but for linux-2.6.23.y
I am getting:

> git fetch linux-2.6.23.y
Cannot get the repository state from http://www.kernel.org/pub/scm/linux/kernel/git/stable/linux-2.6.23.y.git

I wonder if I have misconfigured something or there is some difference
between 2.6.22.y and 2.6.23.y on server side.

Please note, I cannot use git or ssh instead of http, because I am behind
corporate firewall/proxy.

Richard