Woot.

File Hashes for 5.1.3 32bit

Sha1 F5AB4D588ADBEC4D0645824A05AA043D28628A1C

MD5  9E8CD3C8F877D14D52289EF7933B37D5

File Hashes for 5.1.3 64bit

Sha1 E49C5DFED0F0932EB7A6116E58E786387BF89E6E

MD5  1CD16B802462D634908BB50EC8CE083B

If you have a hashing tool, try verifying that sanscreen build, and see if the hashes match.

http://beeblebrox.org/

Is a good one - install it, and when you right click -> properties a file in Windows explorer, there a tab for getting  the hash of a file