all estimate failed error on amanda client

[David Newman]

Greetings. I have installed Amanda on two FreeBSD 5.2.1 boxes, Host A and 
Host B. Host A is the Amanda server, and has the amanda-server package 
installed from ports. Host B has the amanda-client package. I've added a 
couple of Host B's partitions in Host A's disklist.

I'm getting this error in the nightly Amanda reports:
hostb /usr/home lev 0 FAILED [disk /usr/home, all estimate failed]
hostb /var lev 0 FAILED [disk /var, all estimate failed]
The backups on host A are working fine. On the client (host B) I've 
followed the directions here:

http://amanda.sourceforge.net/docs/install.html#id2539781
There is no firewall or other external impediment between the two boxes.
Both boxes run amanda as user "operator" which by default in FreeBSD has 
no home directory. I have placed identical .amandahosts files in the root 
directory of both boxes.

Any clues as to why backups of Host B are failing?
thanks
dn