I think I know. Now.
In addition to changing the way records need to be requested from LC, LC also changed the format of those records. But I believe that LC also has a cache of records that exists to speed up requests, and records in that cache used the old format. That explains why the terms I was using for testing were all successful—they were in the cache; why some fields had inconsistent results (one heading verified, one failed); and other records were complete failures. The complete failures were for things not in the cache, which came through in the unexpected new format.
I have made allowance for the new format in my code, and I have then had success with all of the examples people have sent me.
So I need to find a USB drive (long story) and then I can make a new installer.
Gary L. Strawn
Northwestern University Libraries
1970 Campus Drive, Evanston IL 60208-2300
e-mail: [log in to unmask]
storage facility: 847/467-4619
authority toolkit documentation: http://bit.ly/1Hl1jST
Forsan et haec olim meminisse iuvabit
My 370 verification is still not working, but I’m not sure why.