I have compiled bitcoin 0.4 under Visual Studio 2010. I know this isn't supported, but the bug isn't connected to Visual Studio.
inline uint160 Hash160(const std::vector<unsigned char>& vch)
{
uint256 hash1;
SHA256(&vch[0], vch.size(), (unsigned char*)&hash1);
uint160 hash2;
RIPEMD160((unsigned char*)&hash1, sizeof(hash1), (unsigned char*)&hash2);
return hash2;
}