This is because we use os.path.normcase to canonicalize the paths for comparisons.
I was bitten by this bug. My use case is that I run test cases in Windows (case-insensitive paths), while I aggregate and display coverage information later in a Linux box checking out sources from SVN (case-sensitive paths).
I did some changes that worked for me, based in that question in Stack Overflow asked by you some time ago: http://stackoverflow.com/questions/3692261/in-python-how-can-i-get-the-correctly-cased-path-for-a-file
I attach a patch, and I would like you to review these little changes to include them in a future release if possible.
Thanks in advance,
Sorry, was playing with Bitbucket cards and didn't think it would actually do anything!
Fixed in <<changeset 31ca39cb1da5>>.