How to work with submodule?

I tried to do some work on msysgit, but instead I'm fighting
with submodule for a while now. Maybe I haven't understood
something, but for submodule makes git nearly unusable.
Here is what I did.

msysgit ist organized in the following way.

/.git (clone of repo.or.cz/msysgit.git)
/git/.git (clone of repo.or.cz/git/mingw/4msysgit.git)

That is the root of the project is msysgit and as a submodule
git is included. Working on the submodule is fine.

But it I start to work on msysgit itself I get lost.

I have some changes in the submodule and just want to commit
some changes in the root, rebase to origin/master and push
to mob. To make it a bit harder I have some local changes
in the working tree.

This sounds quite simple, but I'm fighting with submodule
for quite some while now.

I think the root of all trouble is that I changed something
in the submodule git and now would like to change few things
in the root. I have a modified submodule and this messes
up everything.

I can't stash, I can't rebase.

I tried to commit the head of the submodule (btw, how should
I call this? I mean, the sha1 of the head of the submodule),
to get a clean git-status.

Now, I can't even switch branches.

How is this ment to work?
I have no clue how I should work with this mess?

I mean, I should be allowed to work on the submodule and somehow
work on the superproject at the same time? But none of my
usual workflow works because I always get trapped by a
modified submodule.

	Steffen