How did you decompress the file? Any options that would have put unwaranted permissions on the dir? Slack 8 come with Black Box if you did a somewhat full install. If you want to rename a directory use the mv(move) command like this:
mv blackbox-0.61.1 [new directory name]
obviously minus the brackets. Linux has no problems with the - hyphen in files, so that's no problem. If you are trying to do things as a user, you might want to 'su' and do things with root permission.