Same thing happened to me. Check the download directory and you should see the Tome3 mpqe, empty, and the tome3.mpqe.part, ~4 gigs. The downloader didn't transfer the data right. I deleted the tome3.mpqe and the tome3.mpqe.part, ran the downloader and downloaded them again. The key to making this work is letting the downloader sit at 7.6/7.6 for as long as it takes for the downloader to close on its own, do NOT cancel/exit it manually as this causes the problem.
EDIT: If tome3.mpqe isn't there at all, indicated by the disc ejected error, try running the downloader again and letting it close on it's own, it may fix it without re-dling tome3.