Permission denied when using sshpass - ssh

Question

I am running HP-UX 11.31, trying to use sshpass to connect to a vendor's system and retrieve a file using sftp. When I run sftp manually, I am able to connect by entering a password. Thus, the command sftp $USERID#$SERVER works fine. The vendor's system prompts for a password with $USERID#$SERVER's password:, then I enter the password by hand and get the sftp prompt.
When I use sshpass I receive a Permission denied (publickey, password) error. My command is sshpass -e sftp $USERID#$SERVER << EOF followed by the commands to change directories, retrieve the desired file, and exit. I have tried adding the BatchMode=no and StrictHostKeyChecking=no parameters to the sftp command, but the result is the same.
What am I doing wrong? How can I make this work?
Please do not tell me to perform a key exchange or lecture me about the security issues involved here. I already know. I have no authority to change the situation.
EDIT: Here is the output of sftp -vvv, as requested:
OpenSSH_5.5p1+sftpfilecontrol-v1.3-hpn13v7, OpenSSL 0.9.8n 24 Mar 2010
HP-UX Secure Shell-A.05.50.014, HP-UX Secure Shell version
debug1: Reading configuration data /opt/ssh/etc/ssh_config
debug3: RNG is ready, skipping seeding
debug2: ssh_connect: needpriv 0
debug1: Connecting to archive.companykitchen.com [199.91.127.120] port 22.
debug1: Connection established.
debug1: identity file /home/pbewig/.ssh/id_rsa type -1
debug1: identity file /home/pbewig/.ssh/id_rsa-cert type -1
debug3: Not a RSA1 key file /home/pbewig/.ssh/id_dsa.
debug2: key_type_from_name: unknown key type '-----BEGIN'
debug3: key_read: missing keytype
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug2: key_type_from_name: unknown key type '-----END'
debug3: key_read: missing keytype
debug1: identity file /home/pbewig/.ssh/id_dsa type 2
debug1: identity file /home/pbewig/.ssh/id_dsa-cert type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_6.6.1p1 Ubuntu-2ubuntu2
debug1: match: OpenSSH_6.6.1p1 Ubuntu-2ubuntu2 pat OpenSSH*
debug1: Remote is NON-HPN aware
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.5p1+sftpfilecontrol-v1.3-hpn13v7
debug2: fd 5 setting O_NONBLOCK
debug3: RNG is ready, skipping seeding
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: AUTH STATE IS 0
debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: ssh-rsa-cert-v00#openssh.com,ssh-dss-cert-v00#openssh.com,ssh-rsa,ssh-dss
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc#lysator.liu.se
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc#lysator.liu.se
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,umac-64#openssh.com,hmac-ripemd160,hmac-ripemd160#openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,umac-64#openssh.com,hmac-ripemd160,hmac-ripemd160#openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: none,zlib#openssh.com,zlib
debug2: kex_parse_kexinit: none,zlib#openssh.com,zlib
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit: first_kex_follows 0
debug2: kex_parse_kexinit: reserved 0
debug2: kex_parse_kexinit: curve25519-sha256#libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: ssh-rsa,ssh-dss,ecdsa-sha2-nistp256,ssh-ed25519
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-gcm#openssh.com,aes256-gcm#openssh.com,chacha20-poly1305#openssh.com,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc#lysator.liu.se
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-gcm#openssh.com,aes256-gcm#openssh.com,chacha20-poly1305#openssh.com,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc#lysator.liu.se
debug2: kex_parse_kexinit: hmac-md5-etm#openssh.com,hmac-sha1-etm#openssh.com,umac-64-etm#openssh.com,umac-128-etm#openssh.com,hmac-sha2-256-etm#openssh.com,hmac-sha2-512-etm#openssh.com,hmac-ripemd160-etm#openssh.com,hmac-sha1-96-etm#openssh.com,hmac-md5-96-etm#openssh.com,hmac-md5,hmac-sha1,umac-64#openssh.com,umac-128#openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,hmac-ripemd160#openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: hmac-md5-etm#openssh.com,hmac-sha1-etm#openssh.com,umac-64-etm#openssh.com,umac-128-etm#openssh.com,hmac-sha2-256-etm#openssh.com,hmac-sha2-512-etm#openssh.com,hmac-ripemd160-etm#openssh.com,hmac-sha1-96-etm#openssh.com,hmac-md5-96-etm#openssh.com,hmac-md5,hmac-sha1,umac-64#openssh.com,umac-128#openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,hmac-ripemd160#openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: none,zlib#openssh.com
debug2: kex_parse_kexinit: none,zlib#openssh.com
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit: first_kex_follows 0
debug2: kex_parse_kexinit: reserved 0
debug2: mac_setup: found hmac-md5
debug1: REQUESTED ENC.NAME is 'aes128-ctr'
debug1: kex: server->client aes128-ctr hmac-md5 none
debug2: mac_setup: found hmac-md5
debug1: REQUESTED ENC.NAME is 'aes128-ctr'
debug1: kex: client->server aes128-ctr hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug2: dh_gen_key: priv key bits set: 135/256
debug2: bits set: 513/1024
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug3: check_host_in_hostfile: host archive.companykitchen.com filename /home/pbewig/.ssh/known_hosts
debug3: check_host_in_hostfile: host archive.companykitchen.com filename /home/pbewig/.ssh/known_hosts
debug3: check_host_in_hostfile: match line 26
debug3: check_host_in_hostfile: host 199.91.127.120 filename /home/pbewig/.ssh/known_hosts
debug3: check_host_in_hostfile: host 199.91.127.120 filename /home/pbewig/.ssh/known_hosts
debug3: check_host_in_hostfile: match line 27
debug1: Host 'archive.companykitchen.com' is known and matches the RSA host key.
debug1: Found key in /home/pbewig/.ssh/known_hosts:26
debug2: bits set: 502/1024
debug1: ssh_rsa_verify: signature correct
debug2: kex_derive_keys
debug2: set_newkeys: mode 1
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug2: set_newkeys: mode 0
debug1: SSH2_MSG_NEWKEYS received
debug1: Roaming not allowed by server
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug2: key: /home/pbewig/.ssh/id_rsa (0)
debug2: key: /home/pbewig/.ssh/id_dsa (40052840)
debug1: Authentications that can continue: publickey,password
debug3: start over, passed a different list publickey,password
debug3: preferred publickey
debug3: authmethod_lookup publickey
debug3: remaining preferred:
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Trying private key: /home/pbewig/.ssh/id_rsa
debug3: no such identity: /home/pbewig/.ssh/id_rsa
debug1: Offering public key: /home/pbewig/.ssh/id_dsa
debug3: send_pubkey_test
debug2: we sent a publickey packet, wait for reply
debug1: Authentications that can continue: publickey,password
debug2: we did not send a packet, disable method
debug1: No more authentication methods to try.
Permission denied (publickey,password).
Connection closed
It seems to be trying to send a public key and ignoring the password from sshpass.