Fixed. I really need to refactor some of the class hierarchy though
https://github.com/adamhathcock/sharpcompress/commit/97bc1865dc767fe06c7e94839beb9d4edb6c8b12
https://github.com/adamhathcock/sharpcompress/commit/97bc1865dc767fe06c7e94839beb9d4edb6c8b12