GWX troubles

[U-84]

i downloaded GWX, tried to install it and it states i don't have a SH3 that is modified to 1.4b patch..so i download 1.4b patch and when i try to install it it states that
C:\Program Files\Ubisoft\SilentHunterIII\missionengine.dll.un known version..
anythoughts on how to fix this?