The torrent download page has the same md5 info:
md5sum 645600788920443b372baae3544acffa SabayonLinux-x86_64-3.4f.iso
Your download size doesn't look right. The torrent download page reports the size as: 4.35 GB (4,674,338,816 byte). Even if your number is in kilobytes, it doesn't make sense (4,194,304 x 1024 = 4,294,967,296).
You may want to try another mirror, or better yet (IMHO), try one of the torrent programs. I'm not familiar with all of them, but some of them will figure out the bad portion of what you have downloaded, and re-download just that portion. However, your whole download may be fubar if the size isn't right.
(EDIT: NM, I see you solved your problem)