git-fast-export hg mutt (24M vs 184M)

Hello,
I just tried to vendor track / import the mutt hg repository into git.
git-fast-export-hg is quiet amazing but the resulting git repository
blows up in size and I have not the slightes clue why.

        git clone git://repo.or.cz/fast-export.git
        hg clone http://dev.mutt.org/hg/mutt

Could someone have a look at this? I used Debian Etch with a git version
I build myself using an ugly script. I had to upgrade mecurial as well
because the version didn't had the cmdlog.py. I used the unstable debian
package for that.

        (thinkpad) [~/work/mutt] git-init-db
        Initialized empty Git repository in .git/
        (thinkpad) [~/work/mutt] ~/work/fast-export/hg-fast-export.sh -r /tmp/mutt

git version 1.5.2.rc0.56.g6169a

        Thomas