Can't scp as user.

[hboetes]

HP Series Wireless LAN Device HP 850, latest firmware.

I've set up the device to accept all service types (see below). I can log in with ssh but while using sftp or scp I get the following error.

% scp wclhau02.lhau.sigaut.org:startup.cfg /dev/null        
exec request failed on channel 0

Using scp as user admin using a password works OK. But I'd like to use passphrase authentication to download the configs. What am I missing here?

ssh user boehan service-type all authentication-type publickey assign publickey ssh_pubkey_boehan work-directory /

user-interface vty 0 4
 acl 199 inbound
 authentication-mode scheme
 user privilege level 3
 protocol inbound ssh