Did you compile it yourself? There’s a define in makefile.unix. Something like -DCRYPTOPP_DISABLE_SSE2. Remove that. Else the SHA256_Transform will return the initstate. I had the same problem when switchting to 0.3.6.
That seems to be the root of the problem. I think even the bundled binary for Linux 64 in 0.3.8 was compiled wrong then.