pgcrypto pgp_pub_decrypt with passphrase broken

AFAIKT, pgp_pub_decrypt is broken if you protect your private key with a
passphrase. e.g.

works:
pgp_pub_decrypt( pgp_pub_encrypt( 'secret', dearmor(pubkey) ),
dearmor(privkey) )

fails:
pgp_pub_decrypt( pgp_pub_encrypt( 'secret', dearmor(pubkey) ),
dearmor(privkey),
'passphrase' )

The error maps to PXE_MBUF_SHORT_READ, which is only thrown by mbuf.c,
in the pullf_read_fixed function. This function is called from various
places; tracing the problem back, I believe the problem arises in
process_secret_key from pgp-pubkey.c, on this call to pgp_mpi_read:

case PGP_PUB_RSA_ENCRYPT_SIGN:
res = pgp_mpi_read(pkt, &pk->sec.rsa.d);
if (res < 0)
break;

That's as far back as I went (just throwing in fprintf statements to
trace things).

PostgreSQL 9.0.3
Keys created by GPG 1.4.10

Any ideas how to fix this?

-Ron-