What is your client connect string (if you put the password on the command line, please sanitize it)
I use the following:
smbclient //hostname/share -U DOMAIN\\username
I am then prompted for the password.
One thing that you may need to look at is with the offsite hosting, is the ip address of the remote server in the same range as yours
ex:
local ip range: 172.16.9.x
remote ip range: 192.168.1.x
samba will not normally be able to hop the network translation. Remember, the SMB protocol is non-routable so it is limited to your network only