The MD5 check shows that it completed successfully and not that there was a problem with it. The windows error 0 (0x00000000), not really an error in this case = The operation completed successfully.
@ justinckh
Try a repair of avast. Add Remove programs, select 'avast! Anti-Virus,' click the Change/Remove button and scroll down to Repair, click next and follow.
Thai has been know to clear this versions inconsistency in the program.