Interactive Rebase Bug On a Submodule

SourceTree v1.6.2.1 on Mac OSX v10.8.3

Interactive Rebase works well in non-git-submodule repositories, but when I try to do so on a git-submodule repository, it errors out:

git -c diff.mnemonicprefix=false -c core.quotepath=false -c sequence.editor='/Users/jeff/Applications/SourceTree.app/Contents/Resources/stree_gri' -c core.editor='/Users/jeff/Applications/SourceTree.app/Contents/Resources/stree_gri' rebase -i --autosquash
Could not execute editor

A dialog box with a text edit box labeled "Enter commit message" appears, and although I do not know what happens if I were to input something, clicking the dialog "Commit" button without any input text then gives me the following:

git -c diff.mnemonicprefix=false -c core.quotepath=false -c sequence.editor='/Users/jeff/Applications/SourceTree.app/Contents/Resources/stree_gri' -c core.editor='/Users/jeff/Applications/SourceTree.app/Contents/Resources/stree_gri' rebase -i --autosquash
Rebasing (17/17)
Successfully rebased and updated refs/heads/dev.
Completed successfully

No changes are made to the git repository as expected, but no interactive rebase dialog as I did hope for.

You can (hopefully!) reproduce this bug by cloning a copy of the TTcards repository at https://github.com/i8degrees/ttcards and attempting to interactively rebase any of the git-submodules – json_spirit, nomJSON, gamelib. Note that it (should) work inside the base repository (TTcards).

Thank you for your efforts,
Jeff

P.S. I find little reason to use the git command line now with this new feature :-D