darcs init --repo R
cd R
touch foo
darcs add foo
rm foo
darcs wh -> "No changes!"
touch foo
darcs add foo 

the final add errors with
"The following file is already in the repository;
note that to ensure portability we don't allow
files that differ only in case. Use --case-ok to override this:
...
darcs failed: No files were added"

However, darcs wh shows the file as being added.

This probably isn't that likely to occur, but it'd be a slightly strange
error for a user.

This is probably easy to fix. I propose to set the milestone to 2.10.

I don't really have an opinion (or at this stage much right to comment, 
but I think it's harmless to just tentatively set the milestone)