ls -t example.com not working

[Jay W. Reffner]

Everytime I use nslookup on either of my name servers to do a listing of
a particular kind of record, it spits the following error message out
with no log or explanation of why.  Any thoughts?  It happens on any
record type, not just MX records.

> ls -t MX findlay.edu
[ns1.example.com]
*** Can't list domain findlay.edu: Unspecified error
>

lookup work just fine otherwise, even reverse lookups.  It's only when I
try to do a listing of the records.

Thanks,
Jay W. Reffner