Deleted folder keeps showing up?

I made a branch and deleted a folder there with git rm -rf foldername. So now i have to branches, A with the folder and B without the folder.

I'm on B, the folder is not there. Then I check out A, the folder shows up like it should. When I check out B again, the folder is still there.

A git rm -rf folder gives me:

	fatal: pathspec 'folder/' did not match any files

, so git is not tracking the folder.

I can rm -rf the filder without git and start the whole game from the beginning, but there has to be a better way?

Strange enough this happens just to two folders I removed, with others there is no problem.

-benjamin