Submodules and merge conflicts

We have a git repository with 2 submodules structured like this:
-Root
 -Src
    -Scripts [Submodule]
    -Kernel [Submodule]
    -Web

When someone makes changes in the Kernel submodule, the sha1 of the submodule changes. This means that the repository that uses this submodule also changes because the link to the submodule changes. This very often causes confusion. Co-workers very often get merge-conflicts on the submodule sha1 which are annoying and confusing.

The reason we like using submodules instead of having one larger repository is that there are seperate teams working on each module. We also use other version numbers voor the kernel and the appllications using the kernel.

Instead of using the sha1 of a specific revision in the submodule, I would find it more logical to use a branch-name or tag. This way you can commit on the submodule without having to commit the new submodule revision to the main repository also.

I would like to hear your thoughts on this. Maybe we are using submodules wrong, or maybe this is already possible.

Henk Westhuis