Dear Catherine,
I am using conn v13i on both Mac and PC. I believe that your odd label is reflected to some internal error in Matlab. I had one the same problem when I re-installed Matlab.
The solution is simple: remove conn from Matlab path, delete all previous versions of conn (make sure that is deleted from program files if you used it in PC and installed in SPM folder). Download new version, and set up it. Works perfectly for me.
alla